Light Electric Vehicle: The HCF-305 - JP Cruiser - Electric Scooter Users Forum
Maintenance and Repairs on the HCF-305
Maintenance and Repairs on the HCF-305
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Have any HCF-305 Scooter stories, gripes, adventures, modified rigs, technical tips, photos, or video clips?
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Special Salute: Randy Wulf's HCF-305

(good grief, Randy's hauling capacity puts me to shame)

If you are, in fact, offering maintenance and service for the HCF-305, to the public, please send us your full contact information and we'll post it in this section.
If you have any technical information and electrical schematics on the HCF-305, please email it in and we'll post it for the benefit of everyone.

Service and Repairs for the HCF-305:

Ordering Original Factory Issue Parts for the HCF-305:
Be advised that there seems to have been no improvements, and no new parts made since 2004.

Recommended replacement tire for the HCF-305
Street tread, 50psi, is highly recommended over OEM 30psi knobby tread

Replacement tires and inner tubes for the HCF-305 Scooter:
The original knobby tread tires of the HCF-305 only last for about 46% of the mileage of 27" tires on a bicycle.  Those 12-1/2" diameter tires, made of a nylon composite, take a heavy beating, due to their small diameter.
The 5th drive wheel, and the front wheels, will last about 700 - 800 miles. The rear side wheels will last about 800 - 900 miles. Stay posted for further tests on more durable nylon composition tires with street treads.
The HCF-305 requires a replacement tire of the following size:
12-1/2 x2-1/4 R (57-203)
A ETRTO (European Tire and Rim Technical Organization) size marked 57-203 indicates the width of 57 mm and the tire inner diameter of 203mm. This designation is clear and allows an unequivocal match with the corresponding rim size.
12-1/2"x2-1/4" inch size designation, although commonly used, is less accurate. A tire marked 12-1/2 x 2-1/4 indicates an approximate outer diameter of 12-1/2 inches, the tire section width of 2-1/4 inches.

Click the below link to order replacement tire(s). Listed as Item Number: TIR-1250, the price was $17.95 + Sales Tax + Shipping/Handling (for example, S/H for my last order was $ 11.87, for 7 items = $ 1.70 each).

"Qing Da" is the actual brand name, of Chinese manufacture, is made of vulcanized rubber, with internal cotton radial reinforcement threads. It's significant that they inflate to 50p.s.i. (versus 30p.s.i. for the OEM HCF-305 knobby tires). But go ahead and top them off at 55p.s.i., and enjoy the best possible rolling performance for 12-1/2" diameter tires.

*** Important Note:  Be sure to replace these tires as soon as the tread wears smooth.  A Qing Da tire can quickly progress from worn-smooth, to threadbare, to a violent blow-out, within 5 miles (8 kilometers) if on the 5th drive wheel, or on the curb side (= the downhill slope of the road surface) of the vehicle.  A worn-smooth tire, on either of the two wheels on the road centerline side (= the uphill slope of the road surface), can possibly be run, if necessary, for 15 miles (24 kilometers) before a blow-out.   

Click here to go directly to the Electric Scooter Parts website

12-1/2" x 2.25" with bent angle valve stem

Click the below link to order replacement inner tube(s). Listed as Item Number: TUB-125HDBV, the price is $13.95 each + Sales Tax + Shipping/Handling.
"Cheng Shin" is the actual brand name, manufactured in Taiwan, weighs in at 10 oz (280 grams), is as heavy duty as the OEM thorn-proof inner tube.
I've logged over 4,000 miles so far on my HCF-305, with the OEM inner tubes, with only one slow leak, so far.  But I have had 3 blow-outs, due to trying to run too far on worn-smooth tires (see "tires" above for more info).
It's a good idea to have several of these tubes on hand, as the OEM tubes, while heavy duty, are now 6 or 7 years old, and way past their expected lifespan.  Also, these heavy-duty tubes do not patch reliably with a typical vulcanized patch.  In my experience, it's always better to toss a damaged heavy-duty tube and replace it with a new one.

Click here to go directly to the Electric Scooter Parts website

Replacement LED headlight for the HCF-305

Replacement LED Headlight for the HCF-305:
I have just installed a dual set of LEDtronics LED headlights for my HCF-305.
The unusual spacing of multiple, low watt LED lights also greatly reduces the painful LED "arc light" effect and is easy on the eyes for on-coming motorists. Each 12VDC light (= 2 lights wired in series for the 24VDC system) is composed of no less than 44 LEDs that throws a beam as bright as a 14 watt halogen spotlight, while only drawing 3.3 watts each.
That translates into safer nighttime driving, at full cruising speed.
Cost was $59.50 U.S. dollars, each + shipping.
Order Part# PAR36-XCW-014N-001

Replacement 24VDC LED tail-brake light

Replacement LED Tail-Brake Light for the HCF-305: 
LED Shop Online, based in Australia, offers a dual pin replacement LED light that not only uses less current, but burns much brighter.
A compact unit of no less than 24 Red LEDs, this 24VDC hyperbright unit does the job.
A set of 2 tail-brake lights cost about $ 30.00 +  15.00 shipping (U.S. dollars).
Order Product #0200, at the below link:


Turn Signal Indicator Light:
The HCF-305 does not come equipped with turn signal indicators.
This is disturbing because I sometimes attempt to signal a turn  -only find the turn signal switch already engaged. Some motorists in my town think I'm some sort of a jerk, as they're hesitant to pass me because my turn signal may sometimes be signalling a left turn, apparently for blocks and blocks and blocks.
To remedy this problem, I've installed a pair of low current drain amber LED left and right turn signal indicators. Both are mounted on top of the handlebar cowling, aimed directly into the eyes of the vehicle operator, as the LEDs are not easily visible in bright sunlight. A cowling will soon be fashioned over the LEDs to make them more visible in bright sunlight.
The LEDs use very little current  -and there is no noticeable dimming/current drain on the front turn signal lights, which they're wired in to.
Go to this link to order the indicators, at a cost of $ 0.90 each + $ 4.00 shipping (from Thailand):
And order:
Yellow Round 24V Panel-Mount LED


Optibelt Omega 825-5M-A Replacement Drive Belt for the HCF-305:
The OEM drive belt on my HCF-305 lasted about 700 - 800 miles of hard use, at maximum cruising speed, with the trailer in tow. The teeth of the belt don't wear out, but the belt will eventually develop a tear across the width of the belt. The tiny toothed cog, on the motor shaft, seems to put a stress on the stiff reinforcement fibers in the belt, eventually breaking down as the belt makes a tight turns around the engine cog.
I also discovered that when I recently replaced the tire on the 5th wheel (drive wheel), I forgot to adjust the axle of the wheel so that it was exactly parallel to the shaft of the motor.
A simple check can be performed by lining a straight edge along the outside face of the large belt gear (on the wheel), to the outside edge of the washer on the small belt gear (on the motor), and carefully adjusting the wheel axle until the straight edge lines up with the washer on the small belt gear and the belt has the proper tension.
After aligning the belt, tighten the belt, with the left and right belt tension adjustment nuts (accessable only from the rear of the vehicle) until it is taught  -but no more. Double-check that the motor shaft and wheel axle are still parallel and re-adjust if necessary.
Another issue with the Optibelt Omega drive belt is that it is simply not designed to hold up under heavy outdoor, open road use.  Specifically, small (3/32" or 2mm) pebbles (or glass) that may occasionally kick up from the road and lodge in the cogs of the belt, embed themselves, and quickly bury deeply into the belt and destroy the internal reinforcing fibers.  This is the equivalent of a hole in the belt, of the same diameter as the pebble, causing a weakening in the belt that a later break failure in the belt can always be traced back to.  A partial solution to this is to immediately stop your HCF-305 whenever you hear a sudden, unmistakeable ".. thump-thump-thump..." sound coming from the rear of the vehicle when driving.  Using a flashlight (even in daylight), carefully check the 20mm cogs on the inside of the belt and carefully remove (with a pocket knife, if necessary) the small pebble, hopefully before it has the chance to embed itself and do permanent damage.      
Your drive belt will now run clean and true, subjecting it to far less stress, and 1,000 miles of hard use can now be expected.
Go to the following link to order a replacement belt:
Order Part#:
305 JP Cruiser Belt, at $ 29.95 + $ 6.00 shipping

Be sure to always have a spare belt on hand, as local suppliers do not stock the unusual 20mm Optibelt Omega belt width.

All Web Scooters:
All Web Scooters has discontinued the HCF-305, but Bob, the owner, is knowledgeable, helpful, and has plenty of replacement HCF-305 OEM parts in stock.

The staff can only be reached by phone, by the way: 877-570-6961

Here's the link to the All Web Scooters website:


Sasser Distributing Company
2500 Highway 70 West
Goldsboro, North Carolina 27530 United States
Toll Free:  800-672-0475
Tel: 919-735-0475
Fax: 919-736-2076
Their customer service is prompt in taking your order, with delivery, to California, for example, taking about 10 calendar days.
But they are not in a position to render technical advice and service.

Issues with the HCF-305  -and How To Correct Them:

- The batteries originally installed in the HCF-305 are simply not designed to cruise at 12mph for any length of time. The HCF-305, like many electric powered "fun" vehicles, is powered by compact and lightweight sealed lead acid batteries (sla's for short) that, while are deep cycle, are not true fast discharge batteries. In short, the batteries will quickly "boil off" (deplete) their electrolyte after several test runs, 5 to 7 miles each, on a flat, level, paved surface, for about 25 to 30 total miles. 
The best solution for this is to replace the OEM batteries with a set of four PowerSonic PSH-12180NB-FR batteries, add standard battery electrolyte solution to the cells (details below).
But don't rush to condem the HCF-305 manufacturer, as a visit to any local electric car club meeting (check out the "Electric Automobile Association" link below) will reveal that serious battery issues commonly plague almost all electric car owners. Even the popular  -and pricey, hybrid gas/electric cars quickly develop problems with battery pack performance, which become obvious when the owner attempts to run errands around the community using electric power alone.
I've found the solution to the HCF-305 battery issues, as my specially modified battery pack is doing the job quite well. Stay posted.  

- Stability: Out of the crate, when set up according to the HCF-305 Operator Manual, the steering column of the HCF-305 has excessive play. This looseness degrades the stability of the vehicle, creating a disturbing "shimmy" effect, not unlike that of a worn out hydraulic steering dampener in a typical full size auto. But this is easily corrected. Just above the steering column bolt-on joint, that is part of the initial owner-operator assembly and setup, there is also a clamp fitted with two 5mm hex head bolts (see photo below), that is not fully explained in the setup procedure. To access this clamp, remove the screws securing the top of the black rubber boot, and pull it down, exposing the clamp. Tighten both bolts to a snug fit.
The rake angle of the HCF-305's front wheels is backwards! Look carefully at any bicycle, or motorcycle, and you'll notice that the front wheel slants well forward of the handlebars. A typical motorcycle, for example, has a positive rake angle of about 30 degrees. The rake angle of a well designed bicycle, or motorcycle, provides inherent stability, so that the rider can easily ride without any hands on the handlebars, yet continue in a straight line. But with the HCF-305, the problem can be corrected. The engineer who designed the HCF-305 seems to have provided for a good, positive rake angle, but, somehow, down the line, the front wheel suspension was reversed (backwards). A quick examination underneath will reveal that the front wheels need to be removed, leaving the brakes in place on the wheels. Both wheels are held on with standard right-hand thread bolds, with 17mm heads. But be sure to unscrew the tiny lock-screw, on the steering arm, first. Then the entire front swing arm / headset bearings / steering arm joint, on each side, needs to be removed and switched left and right with each other (leave the shock absorbers in place on the frame). The steering arm, underneath the headset bearings, (also holds the wheel axle bolt), will need to be installed upside down this time. But first, the original M10-1.5 pitch headset bolt needs to have an additional 11mm of thread cut into it to properly fit into the now upside down steering arm (a simple handyman project). The brakes (actually a drum, mounted permanently on the wheel hub, encircled by a removable steel compression band), are designed to primarily stop forward motion, so will have to remain on their original sides and orientation. After the adjustments, the front wheels will extend forward an inch or two, and the steering tie rods will now assume a more natural, horizontal position. My HCF-305 now glides over bumps and rough roads much more smoother. Changing the HCF-305's front wheel suspension to a proper rake angle will reduce stress on the steering headset bearings, so that they will now absorb bumps, at the angle they were designed to do, and pass the shock of the bumps directly to the shock absorbers, which will also now be in a better able to dissipate those impacts. But the above steps are not a cure-all. My HCF-305 now leans slightly out of the turn, and tends to veer left and right, from a straight line, while driving, but the the over-all handling of the vehicle is definitely improved. So feel free to alter the front-end suspension, but at your own risk. Stay posted for detailed photos and info on this.
The HCF-305 actually has 5 - 12.5" diameter wheels. The 5th wheel is positioned directly under the rider, as the drive wheel. The vehicle has independent suspension on 4 wheels. But problem is that the 5th wheel is a hard tail, and unlike the other wheels, does not have a shock absorber. This can sometimes cause an unnerving side-to-side rocking motion, when on uneven surfaces, that will sometimes make the HCF-305 feel unstable. One way to alleviate the problem is to inflate the 5th wheel (the power wheel) to 40psi, and the other 4 wheels to 45psi.
Another adjustment is to tighten all four shock absorbers down to their maximum stiffness, easily done by grasping the knurled adjustment ring and spring, with your bare hands, and screwing it down, compressing the external spring. This simple procedure can create a "bone shaker" ride over rough surfaces, but greatly enhances over-all stability and efficiency of the battery pack. 
Yet another fix is to get rid of the standard seat that came with the vehicle and replace it with a form-fitting bucket seat, with a lower center of gravity, and positioned 2-3 inches forward, to enable the front wheels to provide stability. The bucket seat will hold the rider firmly in place, whereas the standard flat, wide seat allows the rider to shift side-to-side, tending to exaggerate stability issues with the HCF-305.
With the above changes made, the HCF-305 is actually quite stable. It simply feels unstable, due to the road vibration (when compared to an automobile) and the way the HCF-305 does not lean into turns. But strapped into the high-back bucket seat and wearing a bicycle helmet, I've tried to "roll" it by taking sharp turns at maximum speed, but the vehicle holds well in all driving conditions, even after the custom roof was added. 
- The HCF-305 motor overload sensor, a valuable feature that will prevent the motor from overheating and burning out, the sensor-activated circuit breaker can sometimes kick in at the darndest times, such as when speeding through a busy intersection, etc.. A fast run at maximum cruising speed (13.7 mph), for about 4.25 miles, will raise the motor temperature to 126 degrees Fahrenheit, causing a heat sensor, inside the motor, to signal the controller, which shuts down the power, bringing the HCF-305 to come to a complete stop. A short wait, of a few minutes, is all it takes for the motor to cool off, and the vehicle's circuit breaker can be reset.
But there's a way to get around this:  I've installed a "Micronta" model #63-842 (a 15 year old unit!) indoor-outdoor digital thermometer on the vehicle, with the remote wired outdoor sensor taped to the bare aluminum end plate of the HCF-305 drive motor. The tape is a small patch of high-tack foam tape that will insulate the sensor from outside temperature interference, and read the motor heat only. The "Micronta" unit maxes out at 123 degrees Fahrenheit, displaying "HHH", signaling me to lower my cruising speed, and acceleration, before the motor begins to overheat and auto-shuts down.
But this trait, overheating and automatic shut-down of the motor, can be worked around by simply lowering the cruising speed to about 12.5 mph, and easing back on the acceleration. Doing so will allow the motor to run at up to 145-150 degrees Fahrenheit, before the controller trips out the circuit breaker shuts down the HCF-305. I'm working on a design of radial aluminum cooling fins for the motor, with either a fan blade screwed on to the motor shaft (pulley end)  -or a ram air duct, so that  the motor runs cooler, allowing maximum cruising speed for greater distances. The motor cooling unit could also be designed to provide a heating duct, into the interior. Stay posted.

- Flat tire: A flat tire on the HCF-305 is a rare event. Carrying a spare for the HCF-305 is not a practical option, since the front wheels are not interchangeable with the rear wheels, and the 5th powered wheel is not interchangeable with either. In fact, to fix a flat tire on the 5th wheel requires that the entire unit be disassembled.
Anticipating this problem, the HCF manufacturer installed super heavy duty inner tubes in the tires of every HCF-305  -the heaviest inner tubes we've ever seen. They should stand up to a lot of mileage, without a thorn or small tack causing any difficulty. 
One solution to avoiding most flat tires, is the brand name "SLiME" inner tube sealant, a blend of fibers and clotting agents. Removing the valve core, and squirting in 3.4 fluid ounces(100 milliliters) of "SLiME", per HCF-305 tire, through the valve stem, "SLiME" claims to prevent and repair flats. Specifically, those flats caused by puncturing objects up to 1/8"(3mm), through the tread area. Be sure to purchase the "SLiME" formulated for "inner tubes", and not their "tire sealant" formulation, as they are quite different. The best time to do the "SLiME" treatment is just before a series of errands, so as to thoroughly coat the insides of the inner tubes. But the manufacturer of "SLiME" states that it only has a lifetime of about two years, so let the buyer beware of the complications this can pose.
Note:  Don't use the "SLiME" Tube Protector (inner tube liner) with an OEM HCF-305 inner tube, as there's simply not enough room to pack in a liner + heavy duty OEM inner tube inside the OEM tire. 
Don't let a flat tire spoil your outing! Pushing your HCF-305 home, with a dead battery pack, is almost as easy as pushing a bicycle. But pushing your HCF-305, with a flat tire, could be a real drag.
In actual practice, the durability of the tires is excellent. I've logged over 4,000 miles on my HCF-305 without a flat tire.
- The headlight of the HCF-305 is just too weak for nighttime use. Close examination shows the light to be nothing more than a standard 5 watt, 24V tungsten filament bulb. I removed the original headlight and installed better system of two, 4-1/4" diameter, 12 Volt halogen malibu-type floodlights. such as the Intermatic LV504, or equivalent. At 14 watts each, wired in series, and hooked into the original headlight wiring, they function perfectly on the HCF-305's 24 Volt system.
28 watts, the total of both leadlights, is the minimum for nighttime driving at full cruising speed, avoiding glass shards and potholes, etc.. But the twin headlights (with the OEM tail running light) will reduce your cruising range by as much as 40% less than your normal daytime cruising range (20% less if using PowerSonic batteries). Some electric vehicle owners tend to under-estimate the battery drain from headlight use. But the real reason for shorter nighttime cruising range is a combination of headlight drain, plus the 5 watt tail light drain + the 5 watt brake light drain, as well as the fact that ambient temperature is always cooler at night, reducing the available power from the battery pack considerably (see operating temperature notes below). 
But one problem with the new, brighter system is that 33 watts of power are now running through a wiring system that was originally designed to handle only 10 watts.
More detailed information on a simple, custom-made x-y axis light beam adjustment mountings (fashioned from the swivel ball joints of plastic shower heads) is described below.
I've just installed twin 12Volt LED floodlights, wired in series for 24VDC, as they provide the same amount of light  -using only 24% as much current (see photo above).  
But substituting LED lights in the HCF-305 turn signals will require a new 24VDC signal flasher, since the OEM flasher may not function properly with the low load LED's.

Steering Column Clamp:


Modifying OEM 22" handlebar to a 29" Longhorn handlebar:
The HCF-305, being a "scooter", does NOT have pack and pinion steering. This means, that at full cruising speed, the HCF-305 experiences a slight loss of steering control, especially when riding over rough paved surfaces.  I initially planned to install a hydraulic steering dampener in the undercarriage, but simplicity dictated that adding 4" extensions to each end of the handlebars should provide the proper leverage, a well as a natural steering dampener effect.
The steering system of the HCF-305 is well built, tight, and secure. But the turning radius is just too tight for comfortably running the vehicle at full cruising speed.
I machined down two 7/8" diameter hardwood dowels, 7-1/2" long: 4" @ 7/8" diameter + 3-1/2" @ 3/4" diameter. The inside of the handlebars were degreased and the wooden extensions were glued into place and then marine varnished. 


Frame Reinforcement of the Left and Right Rear Wheel Suspension:

Cracked joint of lower frame for rear wheel.

There is a structural weakness in the frame that supports the left and right rear wheel suspension.  Hard driving, at full cruising speed over medium-rough paved surfaces will bend and crack the rear frame, at the welded right-angle joint, and cause both wheels to splay outwards, where the tires meet the pavement.  This causes instability, a rougher ride, and greatly reduces the rolling efficiency of the vehicle.

Wooden truss reinforcement for rear wheels.

To repair this, the left and right rear wheels were carefully straightened to their original positions, the vehicle elevated and both left and right rear wheels were removed.
The right-angle frames holding the wheels were then removed and the cracks were repaired by silver brazing.  Since the failure of the original welds was caused by tension, the silver brazed joints are not expected to be as strong as a true weld repair.  So, after 1,000 miles of hard riding have caused a failure in one of the brazed joints.  But a local welder repaired both joints, to better-than-new condition, for a modest charge.
A 17-5/8" long wooden truss was then fashioned to hold the tops of the right-angle frames firmly in place and parallel so that the wheels will no longer splay.  13/16" square wooden pieces (saturated with super glue, and dried first) were then inserted into the tops of the right-angle frames and bolted onto the 17-5/8" long wooden truss.  Wooden braces were also glued left and right of the vertical support of the seat foundation, to hold everything absolutely rigid and tight.
A 3/4" plywood shim was added (after the above photo was taken) to the top-center of the 17-5/8" long wooden truss, to absorb the weight of the seat and passenger, and properly distribute the weight (and road stresses) onto the left and right rear wheels.
The entire wooden truss assembly was then given a liberal coat of marine varnish and installed.
The riding comfort and stability of the vehicle has been greatly enhanced by this simple modification.    

About Replacement Batteries for the HCF-305:

HCF-305 with a 4-pack of 12v PowerSonic batteries
(note the tiny electronic desulfator unit in top of photo)

PowerSonic PSH-12180NB-FR: 12Volts, 21Amps
The new PowerSonic High-Rate Series Battery

(click here to download PSH-12180NB-FR manufacturer's specifications)

I've installed and had good results with a replacement set of batteries for my HCF-305: Four - 12Volt, 21Amp PowerSonic PSH-12180NB-FR batteries, wired, in pairs, in series, and then parallel wired, producing a 24Volt, 42Amp battery pack.

But further reading on the subject indicates that the batteries will function better if first wired parallel, as 2 - 12 Volt groups, and then wired in series, to produce a 24 Volt battery pack. The reason for this is that a weak battery will not degrade the over-all battery pack as much, in this type of arrangement.

These batteries were actually developed for emergency power backup systems, for computer networks, etc.. Although tried and proven in electric wheel chairs that cruise at 3-4mph, these batteries have not been extensively tested on higher performance powered vehicles. But they are formulated for high-drain usage  -without damage. Also, being agm (absorbed glass mat) batteries, they have a strong tolerance of the shock and vibrations of an electric vehicle environment.

The caution here is that the HCF-305 is unique in that the OEM electronic controller allows the 600 watt motor to run the vehicle at 15.0 mph. This is a world of difference, from running, say, a 600 watt motor in a vehicle that will max out at 4 mph. In short, a set of sla batteries that have successfully run a wheel chair for years can quickly burn out when connected to a high performance electronic controller (as in the HCF-305) that runs a vehicle at 15.0 mph.

The battery pack for the HCF-305, at 24 Volts / 42 Ampere-hours capacity, is just not durable enough to power the vehicle at a 15.0 mph cruising speed. It should have been designed with a 24 Volts / 70 Ampere-hours capacity sealed lead acid/absorbed glass mat battery pack + a 24 Volt / 70 Amp electronic controller, for this type of load. The OEM battery pack was designed to cruise at about 8mph, with occasional 15.0 mph speeds for racing against other mobility scooters out of the stoplight.

But this limitation can be worked around. Read on. 

And another warning:  Don't be tempted to build a custom 24 Volt battery pack that exceeds 40-42 amps. Doing so will quickly burn out the electronic controller. And substituting a higher capacity electronic controller will create a loss of many of the special functions that are unique to the HCF-305's performance and convenience. In short, a high performance, off-brand electronic controller will simply run the motor  -and nothing else.

Upon receiving the delivery of the batteries, I promptly pried off the sealed plastic panel, which covers the six soft rubber valve caps to the cells, and added 1-1/2 fluid ounces (44.4 milliliters) of standard battery electrolyte solution (an over-the-counter product of 35% sulfuric acid and 65% water) to each cell, for a total of 9 fluid ounces (266 milliliters) per battery. The electrolyte level just needs to cover the lead plates, and no more. Standard lead acid batteries require topping off with an electrolyte level of almost 1/2" over the lead plates, but your sla agm batteries are better off with less.
Breaking open and "topping off" a perfectly good set of new batteries and voiding the warranty may sound shocking and radical to most people. But, after thoroughly reading up on the subject, I came to the conclusion that my judgement is correct  -and the advice of the battery specialists is wrong. You see, sealed acid batteries are, by their very nature, "starved electrolyte", due to the simple fact that the fiberglass mats between the lead plates are only 95% saturated, in order to make them spill proof. As such, water depletion of the "sealed" system is a constant concern. Performance can only take a back seat when a battery is designed this way.

Another benefit of flooding a sealed lead acid battery is to provide an inherent ability to dissipate heat. That is, typical flooded deep cycle batteries may normally become warm to the touch, either from heavy use, or from quick charging, but if a sealed lead acid battery ever becomes warm to the touch, the internal lead/glass mat cells, more than likely, have dried up and burned out, due to the complete inability of the empty spaces in the cells to dissipate intense heat away from the lead plates.

And if the new high-rate sealed lead acid batteries were truly reliable, then why haven't the golf cart manufacturers installed them, making their vehicles lighter and more responsive? I feel that those relatively expensive, compact, and high-performance sealed lead acid batteries must be flooded (electrolyte added), to enjoy their maximum potential.

The electrolyte added, I replaced the cell caps back onto the battery and took a push-pin and punctured a hole into the middle of each of the six soft rubber cell caps, to eliminate the internal vacuum that happens as the batteries cool back down to ambient temperature, causing the electrolyte in the glass mats to deplete to less than 95% saturation.  That done, the plastic panel was replaced on the top of each battery and taped shut, with the ends uncovered to allow for venting.  Flooded batteries, simply, do not have to be sealed.

Sealed lead acid batteries produce hydrogen gas (and also oxygen, via electrolysis), internally, which bleeds through the one-way, valve caps, and prevents outside air from entering into the battery. Oxygen, especially, will damage the thin lead plates of a typical, compact sealed lead acid battery, so they were designed to best operate in an internal atmosphere of hydrogen gas. Completely covering the lead plates and fiberglass mats with electrolyte solution also prevents direct contact with air. Once this is done, the battery will only need to be occasionally "topped off" with standard electrolyte solution (unlike standard automotive batteries, don't use distilled water for this), for regular maintenance.

Measuring the same height, the same length, and half the width of the standard issue HCF-305 batteries, the pack of four PowerSonic replacement batteries fit snugly into the HCF-305 battery compartment. Be sure to fashion a means to tightly secure each and every battery into position. The HCF-305 has minimal sized shock absorbers and any bumping and movement of the batteries WILL cause the battery cables to come untightened and loose. And the amperage running in the battery cables is strong enough to melt steel.

A 7/8" closed-cell Insulite foam pad, covering the entire floor of the battery compartment, was added as a shock absorber, to cushion the batteries from road shock, as well as eliminate the problem of electrolyte solution flooding out of the batteryis and into the battery compartment and cables.

Although the new batteries arrived pre-charged, it is imperative that the modified "topped off" set of batteries were given a full, overnight charge, using the standard HCF-305 charger. After charging, each battery will test at 13.5-14 Volts  -yet another advantage of adding standard electrolyte to the sla batteries, adding extra "pep" to the performance, without overloading the HCF-305 electronic controller.

It makes no sense to enhance the battery pack performance on the HCF-305, if full power is restricted from reaching the electronic controller, and the motor. Specifically, the OEM 12AWG wiring harness needs to be replaced with a custom, more robust 10AWG automotive wiring harness.

The problem with the OEM 12AWG wiring is that it is really not adequate for fast discharge characteristics of running the HCF-305 at full cruising speed. The OEM 600 watt motor is also wired with the same 12AWG wiring, indicating that the motor manufacturer never intended that their motor be run that hard.

Also, the cross-section of the OEM 12AWG wire has no less than 65 fine copper wires, that are extremely vulnerable to trace amounts of battery electrolyte wicking deep into the wiring (acid wicked in and damaged 10-1/2" / 27cm of wire on my HCF-305!). Whereas standard 10AWG automotive wiring is much heavier, capable of handling 60% more current and, more importantly, the cross-section a typical 10AWG automotive wire has about 19 coarse copper wires that are far less likely to absorb battery electrolyte, and if that happens, is somewhat less susceptable to acid corrosion eating through the wiring, blocking the high flow of current.

Once fabricated, the lugged contacts, on the new red and black 10AWG battery pack cables, need to be carefully "tinned" with an electrical rosin core solder, to make the battery wiring more efficient. The battery pack cables have battery contacts that are originally crimped on, which can sometimes restrict large amounts of current to freely pass through, causing a "hot spot". Lead-based solder, with a much lower melting point (374 degrees Fahrenheit) than lead-free solder (430 degrees Fahrenheit) will freely melt into the copper braids of the wiring, with a 75 watt soldering gun, for a clean, heavy flow of DC current. Lead-free solder will probably require a butane pencil torch, to overcome the heat-sink nature of the heavy copper wire and quickly melt the solder well into the connector and wire. But this step is not absolutely required, as physical checks of the battery pack wiring, even during heavy use, has never found the wiring warm to the touch, even though the wiring still seems light for the task.

But, if you choose to add electrolyte to your sla batteries, "tinning" is a required step. The reason is that there will always be trace amounts of electrolyte that somehow make it outside of the battery (from riding the vehicle over rough surfaces, etc.), and make contact with the battery terminals and battery connections. And once on the connections, an even miniscule amount of electrolyte can quickly wick into the braided copper wiring, to do its mischief and impede in the proper flow of DC current. "Tinning", while not preventing this corrosion, will effectively ensure a clean, heavy flow of DC current through the wiring at all times.

Initially, I simply cut off the OEM wiring connectors and replaced them with heavy duty 12-10 AWG ring terminals, for a #8-#10 stud, crimped onto the battery pack cables and "tinned" with liberal amount of solder. And then applied and worked in liberal amounts of special battery terminal grease, which also has special inhibitors to neutralize battery electrolyte.

The battery terminals and wiring connectors must be clean at all times. The powdery deposits that sometimes form on the terminals are result of battery acid corrosion. The battery pack can usually be charged through corroded contacts. But the high rate of battery discharge, required for driving the vehicle, will create "hot spots" where corrosion is present, greatly diminishing performance of the vehicle.

To remove corrosion from the battery pack, remove the wiring connectors from the battery terminals, and remove the batteries from the vehicle. Clean the deposits off by wetting down an old toothbrush and sprinkling it with baking soda, straight from the box, and scrubbing the terminals and connectors. Dipping a toothbrush in Coca-Cola also works well in removing acid corrosion.

If this doesn't completely remove all corrosion, take a small brass bristle brush (the size of a tooth brush) and carefully remove the remainder of the corrosion from the battery terminals and connectors. Any stubborn areas can be removed with a small, sharp knife. Medium-coarse steel (soap-free) can also be used ensure a solid electrical connection. Wipe dry and allow  everything to air dry completely. To prevent corrosive deposits from forming again, coat the terminals and wiring connectors with a liberal application of dielectric grease  -or even better: A silicone dielectric terminal grease.

The new battery pack also needs to be gradually "broken in". That is, run your HCF-305 no more that 2 miles on the first test run. Then completely recharge the battery pack. Run your HCF-305 no more than 4 miles on the second run, and recharge. 7 miles on the third run, 9 miles on the fourth run, 11 miles on the fifth run, and 14 miles on the sixth run. Your battery pack is now ready for hard use.

The HCF-305 should now have a maximum range of 15.5 miles on a smooth surface in open country, or 9.5 miles in neighborhood stop-and-go traffic, at 14 miles per hour.

The first test run on the HCF-305, the vehicle was driven at full speed, for about 8-1/2 miles (but don't do what I did  -see above), before the heat sensor in the motor caused the circuit breaker button to fully extend out, turning off the power to the vehicle. Following the instructions of the HCF-305 Operator's Manual, the vehicle (actually, the motor) was allowed to cool off for about 20 minutes, before the circuit breaker button was pushed back into the flush (reset) position, and the HCF-305 was turned on and driven home, about a mile away, with power to spare.

Before the second test run, a digital speedometer/odometer was installed to provide greater accuracy. A digital odometer is especially useful when operating a Light Electric Vehicle, as it provides a clear, precise display of the remaining mileage on your vehicle.

Here are the results with the PowerSonic battery pack (on a smooth, paved surface, and with the modified bicycle trailer in tow):

Maximum speed: 14mph (22.5kph)

Maximum Range (on a smooth surface, in open country):

                           15.5miles  (24.9 kilometers) @ 14mph (22.5kph)

                           31 miles    (49.9 kilometers) @ 9.2mph (14.8kph)

                           46.5 miles (74.8 kilometers) @ 4.6mph (7.4kph)

Maximum Range (in neighborhood stop-and-go traffic):

                           11 miles (15.3 kilometers) @ 14mph (22.5kph)

                           20.5 miles (30.6 kilometers) @ 9.2mph (14.8kph)

                           31 miles (45.9 kilometers) @ 4.6mph (7.4kph)

The above mileage is at an ambient operating temperature of 70 degrees Fahrenheit. Driving in cold weather can reduce range, and driving in warm weather can increase range as follows:

         100 degrees Fahrenheit: 128% range      With headlight on: 115% range

           90 degrees Fahrenheit: 119% range      With headlight on: 107% range

           80 degrees Fahrenheit: 109% range      With headlight on: 98% range

           70 degrees Fahrenheit: 100% range      With headlight on: 90% range

           60 degrees Fahrenheit:  87% range      With headlight on: 78% range

           50 degrees Fahrenheit:  74% range      With headlight on: 67% range

           40 degrees Fahrenheit:  61% range      With headlight on: 55% range

           30 degrees Fahrenheit:  47% range      With headlight on: 42% range

But the Power-Sonic still provides twice the range from a charge, and an 11% increase in cruising speed, over the standard issue HCF-305 battery pack. After the second test run, the batteries were opened and the electrolyte level inspected. There was no noticeable loss of fluid in the cells.

But note that the above mileages are the maximum that the HCF-305 is capable of.  But driving your HCF-305 until it barely crawls home is commonly known as "batterycide".  That is, doing so will accumulate long-term damage on the battery pack, until it needs to be replaced with a new battery pack, after only achieving 50% if its normal lifespan.  After running the HCF-305 for several years, the mileage chart, below, was formulated.   

Maximum Recommended Range At 15mph Cruising Speed (with maximum battery pack life):

100 degrees Fahrenheit: 17.0 miles .... With dual LED headlights on: 15.3 miles

 90 degrees Fahrenheit: 15.8 miles .... With dual LED headlights on: 14.2 miles

 80 degrees Fahrenheit: 14.5 miles .... With dual LED headlights on: 13.0 miles

 70 degrees Fahrenheit: 13.3 miles .... With dual LED headlights on: 12.0 miles

 60 degrees Fahrenheit: 11.6 miles .... With dual LED headlights on: 10.4 miles

 50 degrees Fahrenheit:  9.8 miles .... With dual LED headlights on:  8.9 miles

 40 degrees Fahrenheit:  8.1 miles .... With dual LED headlights on:  7.3 miles

 30 degrees Fahrenheit:  6.3 miles .... With dual LED headlights on:  5.6 miles


   - Longer life of battery pack

   - True overnight charging (7 - 9 hours)

That said, there is yet another complication, though, the HCF-305 motor overload sensor:

While this valuable feature will prevent the motor from overheating and burning out, the sensor-activated circuit breaker, after about 4-1/4 miles of hard riding (at 15.0 mph) will kick in at the darndest times, such as when speeding through a busy intersection, etc.. At full speed (15.0mph), the heat sensor, inside the aluminum end plate of the motor, signals the electronic controller, which makes the decision to shut down the power, at 126 degrees Fahrenheit, causing the HCF-305 to come to a complete stop. A short wait, of a few minutes, is all it takes for the motor to cool off, and the vehicle's circuit breaker can be reset. Or, a better option, is to accelerate to maximum cruising speed (15.0mph), and then ease back on the throttle until there is a noticeable drop in speed, then slightly twist on the accelerator until the vehicle reaches its 15.0mph normal cruising speed. And you'll cruise like a pro.  Although the motor still has a temperature of 126 degrees Fahrenheit, the controller will allow the HCF-305 to continue to operate because it will no longer predict a rapid rise in temperature, that could cause a motor burnout. Preliminary testing indicates that a sustained cruising speed of about 15.0 mph, the electronic controller will allow the motor to operate at up to temperatures of 145-150 degrees Fahrenheit, without overheating the motor.

The replacement PowerSonic battery pack requires a full 8 hours to charge, before the amber charging led turns green. But a full overnight charge (12-14 hours) is highly recommended. After a full charge, each 12 Volt battery will test at 13.5-14 Volts.

Note that sealed lead acid batteries have a slightly different electrolyte, which influences the terminal voltage. If you have installed a set of PowerSonic batteries  -and chosen not to break them open and add electrolyte, a full charge voltage should read about 12.8 to 14 Volts.

ALWAYS recharge your lead acid battery pack after a good run (4-1/2 to 7-1/2 miles, or more). Failure to do so can cause deterioration of the lead plates.

Also, like Ni-Cad batteries, I've read that lead acid batteries can also develop a memory. This means that after a short test run around the block, for example, the battery pack should not be recharged before storing the vehicle away. Recharging the battery pack, as such, may adversely affect the next cycle, reducing the range. I don't really worry myself with this possibility, but posted it as a precaution.

So far, the results from the new battery pack have been dramatic. Costing about $ 260.00 American dollars, which included shipping (but the price is going up in 2008), I feel that these batteries will provide a compact, yet powerful and reliable high-rate discharge system to power the HCF-305's 600 watt motor.

I've given up on restoring the damaged, original issue WP20-2E batteries. They, simply, can't be rejuvenated.

The PowerSonic batteries, and the unorthodox electrolyte treatment, have, so far, logged over 1,400miles (about 140 charge/discharge cycles) of hard use, running the vehicle at maximum cruising speed.

My HCF-305 is now being run on as many errands around town as possible, to find out how tough these improvised batteries really are. Occasional checks of the battery electrolyte levels required only a light "topping-off" of one cell, of one battery only, with electrolyte (don't use distilled water). The batteries in the battery pack were also occasionally rotated, from front to rear, to distribute wear (if any) evenly on the batteries. I have also presented my findings to the local Electric Auto Association members, of flooding sealed lead acid batteries. Some of the members have the capability to bench test a single PowerSonic battery: Break it open and add electrolyte to the cells and not only duplicate my results, but also run the battery through a rapid series of charge/high-discharge cycles to determine if the concept will work over the long haul, and forsee complications. My only hesitation is that I didn't have a solid two year track record (or 2,000 miles), on my modified PowerSonic battery pack, which was my original goal. Sealed lead acid battery packs, when driven at full speed discharge rates, have lasted somewhere between 1,000 to 2,000 miles (100 to 200 charge-discharge cycles) on other light electric vehicles, which is somewhat useful as a comparison.

The purist may choose to charge their custom battery pack, using four 12 Volt chargers, one for each battery, to ensure a "balanced battery pack". But this is unnecessary with the HCF-305, since the batteries were ordered from the supplier, specified as a matched set. Also, the HCF-305 electronic controller never allows the battery pack to discharge below 40 percent, so a possible weak battery in the pack becomes less of an issue. And periodic rotation (done every time the battery electrolyte level is checked) of the battery arrangement in the pack tends to balance out possible system stress on any one battery. The four 12 Volt battery pack arrangement is also defined a "low voltage traction pack", which is not as maintenance-critical as the newer, higher voltage, multiple battery packs in the newer electric cars on the market. A "balanced battery pack" is essential for a lithium-polymer powered radio controlled model airplane, but not for a pack of four lead acid batteries, carefully protected by the HCF-305 electronic controller.

The new battery pack will soon be wired with a fuse, on each battery, so that a short-circuited battery won't destroy the entire pack. The OEM battery pack wiring harness, oddly, is not fused. Also, the series-parallel arrangement pushes the limits of what an amateur should really attempt on these sort of projects, so stay posted for specific wiring details, complete with photos.


I ordered my replacement set of Power-Sonic Model# PSH-12180NB-FR batteries on the advice of Randy Walker, owner of Battery Plex, a distributor, retailer, and wholesaler of batteries and chargers. Randy has years of battery experience and is supported by battery technicians and specialists who provide professional service and assistance. Don't hesitate to contact him for quick, tried and proven technical advice.
Contact info:
Battery Plex, 6301 North Falls Circle Drive, Fort Lauderdale, Florida 33319
 954-325-9717   fax: 954-714-3272
(Just don't tell him that I recommend breaking open his pristine sealed lead acid batteries and adding electrolyte.) 
While we, as a group, do not yet qualify for quantity discounts, Randy is open to our needs and will consider us, if enough of us HCF-305 owners accumulate and contact Battery Plex, detailing our needs.   

PowerCheq Electronic Battery String Equalizer

PowerCheq Electronic Battery String Equalizers Increase the Mileage of the Battery Pack By 100 Percent!
PowerCheq is a real-time, electronic battery balancing system that equalizes and maintains batteries during charge, discharge, and while sitting idle.  By continuously equalizing individual batteries, within a string, batteries are properly maintained and kept at the same state of charge.  Operation during charging ensures that all batteries will receive a full and equal charge, thus preventing undercharging / overcharging.
As mentioned earlier, the four - 12Volt, 21Amp PowerSonic PSH-12180NB-FR batteries are wired, in pairs, in series, and then parallel wired, to produce a 24 Volt, 42 Amp battery pack.
But it is not well known that, in such a battery pack, the two batteries, attached to the final positive wire to the electronic controller, discharge much faster than the other two batteries, atached to the final negative wire to the electronic controller.
This creates a serious imbalance that not only leaves unused power, in the two negative-end batteries, but also reduces the lifespan of the over-all battery pack  -even with periodic battery rotation.
My initial plan was to wire in a cumbersome, heavy-duty electric switch, with eight wires from the batteries entering one side, and two wires exiting the other side, to the electronic controller.  The switch would be used halfway through the vehicle run, for the return trip home.  The sequence of the battery pack would be completely rearranged (aka battery rotation) and, I figured, would increase the range of the vehicle by 25 percent and extend the overall life of the battery pack.
Yet, at the same time, I heard about the PowerCheq battery string equalizer, which seemed to be far more user-friendly  -and efficient.  But the reviews on the internet seemed less than enthusiastic.  And the manufacturer (PowerDesigners) had removed the device from their website (
After considerable reading on the meager performance gains PowerCheq users reported, I feel that the issue is that the PowerCheq device, which was actually developed for electric wheelchairs and mobility scooters, was, in fact, purchased and installed in full size electric vehicles.  And, as could be expected, the performance gains were, at best, slight, due to sheer size of the batteries.  In short, a PowerCheq battery string equalizer will improve the performance of a 75 Amp-Hour battery, but common sense dictates that only so much power can be transferred through the thin 16awg-18awg PowerCheq wiring.
But things change when the PowerCheq is used with 21 ampere-hours (AH) batteries:  The revolutionary device functions at its best!
The PowerCheq module interconnects the two 12V batteries connected in each 24VDC series string, in the battery pack, creating a bi-directional energy transfer path between the batteries.  The module intelligently equalizes batteries during charge, discharge, and idle periods, keeping them properly maintained at the same state of charge  -critically important to battery life and range of the vehicle battery pack.
Only two PowerCheq devices were needed, as the simple parallel wiring of the battery pack naturally works to balance the 2-12VDC battery strings.

More information about the device can be found at:

Here are the results (on a smooth, paved surface, and with the modified bicycle trailer in tow) with the modified PowerSonic battery pack (broken open and flooded with standard battery electrolyte solution) with two PowerCheq battery string equalizers installed:
Maximum speed: 15mph (24kph)
Maximum Range (on a smooth surface, in open country):
27 miles (43.5 kilometers) @ 15mph (24kph)
54 miles (87 kilometers) @ 9.2mph (14.8kph) *This mileage has been calculated  -not road tested.
81 miles (130 kilometers) @ 4.6mph (7.4kph) *This mileage has been calculated  -not road tested.
Maximum Range (in neighborhood stop-and-go traffic):
19.2 miles (26.7 kilometers) @ 15mph (24kph)
35.8 miles (53.5 kilometers) @ 9.2mph (14.8kph) *This mileage has been calculated  -not road tested.
54.2 miles (80.3 kilometers) @ 4.6mph (7.4kph) *This mileage has been calculated  -not road tested.
The above mileage is at an ambient operating temperature of 70 degrees Fahrenheit.
*** Note that the above is maximum mileages, which places a heavy load on the battery pack, reducing the life of the batteries to 120 charge cycles.
Below is a revised (and preferred) mileage chart that will allow the battery pack to run for 240 charge cycles, or more:
Maximum Recommended Range At 15mph Cruising Speed:
(Specially flooded PowerSonic High-Rate 12 Volt, 21 Amp-Hr, sealed lead acid batteries, with PowerCheq battery balancing electronic modules)
100 degrees Fahrenheit: 17.0 miles .... With dual LED headlights on: 15.3 miles
 90 degrees Fahrenheit: 15.8 miles .... With dual LED headlights on: 14.2 miles
 80 degrees Fahrenheit: 14.5 miles .... With dual LED headlights on: 13.0 miles
 70 degrees Fahrenheit: 13.3 miles .... With dual LED headlights on: 12.0 miles
 60 degrees Fahrenheit: 11.6 miles .... With dual LED headlights on: 10.4 miles
 50 degrees Fahrenheit:  9.8 miles .... With dual LED headlights on:  8.9 miles
 40 degrees Fahrenheit:  8.1 miles .... With dual LED headlights on:  7.3 miles
 30 degrees Fahrenheit:  6.3 miles .... With dual LED headlights on:  5.6 miles

* Above mileages are for typical neighborhood stop-and-go traffic, on a smooth and level road surface.  Okay to run vehicle 50% more miles if open road conditions, with few stops.
PowerCheq Electronic Battery String Equalizers (12V Module: #401-PCHQ-12V-2A) can be purchased, for $ 58.99 each at:

Tough Love - Equalization Charge of the HCF-305 Battery Pack:
Our advice is:  Don't do it.
After several attempts, the process simply does not work on sealed lead acid batteries, even those with the unorthodox flooded treatment.
But, for your information, here is a description of the process, just in case you decide to install standard flooded deep cycle lead acid batteries:
Deep cycle lead acid batteries, over time, will begin to decrease in performance, well before the end of the expected life of the battery pack. This is quite normal. And, with flooded deep cycle lead acid batteries, there is a remedy for this.
As a rule, sealed lead acid battery packs MUST NEVER be equalization charged.
Equalization charging is a battery restoration process where peak charging voltage is simply raised to a higher than normal level. This often involves a steady overcharge, bringing the battery to a gassing, bubbling and hissing state. Equalization charging is often done on a fully charged battery pack, to reduce the time required for the process, which is somewhat risky the first time it's done. Fresh lead plate surface is exposed by the process, at the expense of losing active material, which simply falls to the bottom of the cell in flooded lead acid batteries.
In typical deep cycle flooded lead acid golf cart batteries, equalization is usually done once every 5-10 charge/discharge cycles.
Equalization charge is typically done on a fully charged battery pack.
Never at any time should the battery pack become warm to the touch. The gassing, bubbling and hissing sounds from the battery pack should be clearly audible in a quiet workshop. These sounds actually happen much earlier in the equalization charge, if one were to press their ear against the battery (not recommended). But only reaching a level of clearly audible sounds of the equalization charge, heard from across a quiet room, are necessary to fully resurrect an ailing battery pack. 

Amps Don't Lie:

DHC Specialty 6V/12V 100 Amp Battery Load Tester
Sold by Kragen Auto Parts: $ 29.99

*** Note: This battery load tester is for 6 Volt or 12 Volt batteries only.
*** Note: This type of battery tester was not designed for standard (medium-rate)
              SLA-AGM (sealed lead acid - absorbed glass mat) type batteries.
              Even with my unorthodox flooded High-Rate SLA-AGM's, using this
              tester is a delicate process. But the need to separate the bad batteries,
              from the good batteries, is paramount. Carefully follow the instructions
              below, but do so at your own risk.
A battery load tester is a "must have" tool for the serious electric vehicle enthusiast. Sulfating and plate disintegration occur naturally as batteries age. Re-charging a bad battery only gives it temporary or "surface power". A freshly charged, but worn out battery may accept and hold a surface charge, yet not provide adequate vehicle speed and range.
Also, you must assume that, on the average, 1 in 20 new deep cycle batteries on the market  -even reputable brands, may be bad and defective. Standard procedure for new batteries is to run them through a full charge cycle, followed by an amp load test. Promptly send a battery that fails back for an exchange. Remember: If you choose to break open and flood your sealed lead acid battery, the warranty is voided  -even if the battery was defective. 
If the onboard OEM HCF-305 LED Battery Indicator is a good judge of the over-all health of the battery pack, then a battery load tester will quickly indicate exactly which battery in the pack is malfunctioning. 
You need to know if your battery will hold up under heavy loads and hard running conditions. A battery load tester simulates that load by creating a 50+ amp load/demand on the battery. The analog meter will clearly indicate a battery's ability to "hold up" under load conditions. It's simple to use and will let you know if you need to buy a new battery or not... No more guessing!

Analog dial accurately shows battery voltage:
... as well as actual battery strength.

You must first have the battery fully charged. The surface charge should then be allowed to dissipate before testing. If the battery has been sitting at least several hours (12 hours is even better) you may begin testing.  But, in actual practice, I rarely have the time and patience for this, and Amp-Load test anyway, and with good results. 
Load testing is yet another way of testing a battery. Load test removes amps from a battery  -much like driving your electric vehicle would.
Before using, especially after unpacking the new unit, the needle indicator on the analog guage must be first calibrated:  With the Amp/Load meter laying on a flat level surface, finely adjust the indicator needle, using a small flat-head screwdriver, until the needle points to to "zero" on the volt indicator dial.  
But an even better way is to take a voltage reading of the battery, with an already accurate volt/ohmmeter. Then connect the "+" and "-" clamps of the Amp/Load meter to the battery. With the Amp/Load meter laying on a flat level surface, finely adjust the indicator needle, using a small flat-head screwdriver until the needle points to the exact voltage. Remove one clamp from a battery terminal, reconnect and repeat the process, just to be sure. The unit is now accurately calibrated, for the Volts and Amps that you will actually be measuring. With the clamps removed from the battery, the indicator needle (after calibrating to a 12 Volt battery) will now come to rest, for example at the 0.5 Volt position. But both the Volt meter and Amp meter are still accurately calibrated. 
Connecting the heavy duty insulated clamps to the terminals of an individual 12 Volt battery will instantly produce accurate battery voltage readings on the upper analog scale. Batteries can be accurately, and individually, tested while still wired together in a battery pack.

Volts - to - Amps toggle switch:

Pressing the "-" side of the momentary toggle switch engages the device in the Amps mode, only for as long as the switch is manualy held down.
There's a reason for this.
While the crude, but effective, unit can reliably test flooded lead acid batteries of 7 to 80 Amp Hours capacity, a "load test" stresses the battery with a heavy load, in the form of a short, but rapid drain, created by a hefty 100 Amp manganese wire resistance element shunt grid, inside the heavily vented steel case.
Unfortunately, the specifications included with these devices is appallingly sketchy and incomplete, and the resistance load is fixed and not adjustable. But you do have control over the time of the load test and can use that to your advantage. But a good rule of thumb is if 10 seconds is the suggested maximum load test time, then the device is putting a 100 Amp load on the battery. If 20 seconds is the suggested maximum load test time, then the device is putting a 50 Amp load on the battery.
Next, check manufacturer's specifications for the battery to be tested. The amp load, of the tester, should not exceed the Maximum Short-Duration Discharge Current of the battery. In my case, the 12 Volt, 21 Amp PowerSonic PSH-12180-FR "High-Rate" battery can withstand a maximum of 210 amperes discharge, for up to 10 seconds.
Next, take the AH Rating (Amp Hour Rating) of the battery to be tested, and multiply x1.5 (if a SLA/AGM battery) or x3 (if a standard flooded lead acid battery). Divide the result by the amp load of the load tester. Then multiply times the maximum test time for the load tester.
My 21AH SLA/AGM battery x1.5 = 31.5 / 100 Amps load = .315 x 10 seconds = 3 second maximum test time.
But, still, I never Amp/Load test my batteries for more than one second.  

Although the instructions inside the box recommend a maximum test of no more than 10 seconds, I strongly urge a maximum test time of no more than 3 seconds for these powerful  -but tiny, 12 Volt, 21 Amp PowerSonic batteries.
While under a load test, it's normal for the test Voltage (in the green area) to slowly drop, at a rate of about 0.2 volts per second, as the boiling action inside the battery naturally creates micro-bubbles on the lead plates, temporarily reducing contact of the electrolyte solution. On the other hand, a bad battery will instantly display a load test reading of low Voltage, in the red area.   
The unit generates a considerable amount of heat, and the 12 Volt / 21 Amp sealed lead acid PowerSonic battery (specially broken open and flooded) may also begin to boil inside as the Amp testing period ends. And 3 seconds is plenty of time to test a 12 Volt, 21 Amp batttery, and minimize the risk of damage.
Heat will be your enemy when using this device. Take care so as not to be burned while handling the unit. Also, allow the unit to cool off for a minute or so, before testing the next battery.
Also, the 100 Amp test cables are short in length, so take special care that the steel case does not bridge the battery terminals, creating a disasterous electrical short. The current in a 12 Volt / 21 Amp battery is strong enough to melt steel! 
A brand new, fully charged 12 Volt / 21 Amp PowerSonic battery will read 14.2 Volts, and the guage needle will point well into the upper green area (1,000 cold cranking amps) on the Amp scale (11.7 Volts, under 100 Amp load, to be exact).
An Amp reading in the red (Bad") range, followed by a quick return to a 12 Volt reading, after releasing the test button, is a sure sign of a permanently damaged battery, and should be replaced with a fresh battery. 
Oddly, a well-used 12 Volt / 21 Amp PowerSonic battery (specially flooded), with 1,400 miles / 140 charge cycles of wear, will read just as strong. So far, there is no measurable, predictable decline in battery performance. There's no better testimony for such a well-made battery.
The OEM HCF-305 24VDC battery pack charger can also be easily checked, during the charging process, by simply connecting the battery clamps to the posts, of one battery, and reading the voltage scale. A properly functioning 24VDC charger will register 13.8 Volts on the voltage scale. NEVER press the Amp button on the battey tester while the HCF-305 battery pack is charging.
Yet another useful function of this handy amp/load tester is to determine, and re-label, the Amp-Hour capacity of a used, worn-out lead acid battery.  Really.  I feel that a weak, old lead acid battery, when properly tested and the actual Amp-Hour capacity carefully noted on the battery, is now a completely useful battery that can be applied to many applications, as long as the load is appropriate for the re-labeled battery capacity.
For example, my brand new 12 Volt, 21 Amp-Hour sealed lead acid batteries will be retired (from my light electric vehicle) when the battery pack eventually runs down to 80% capacity, and all of the batteries are now, essentially, 12 Volt, 16 Amp-Hour lead acid batteries.  And they are now more than welcome for use on my portable wind generator and portable sun tracking solar panel, still providing years of reliable service.
But, before those batteries are even retired from my electric vehicle, I periodically do an amp/load test on each of the four batteries, at the same time the battery pack is rotated, front-to-back, and the electrolyte levels are checked.  If the capacity of the ageing batteries have declined an Amp-Hour or two, I revise my maximum mileage chart (compensated for battery temperature) to reflect a reduced range.  Doing so will greatly extend the lifespan of the battery pack, as running, for example, a now 20.0 Amp-Hour (=95% capacity) battery pack, at full range, will cause an early death of the battery pack.   
Note:  The below information applies to 12 Volt, 21 Amp-Hour sealed lead acid batteries, that have been broken open, and flooded, with standard battery electrolyte solution, before installing in an electric vehicle.  Sealed lead acid batteries, that have not been "flooded", should be simply recycled after serving out their useful life in an electric vehicle, as they will lack the characteristics of a long service life.  
Here is a handy chart I use to periodically re-label my ageing, and retired, lead acid batteries, as they slowly decline over time (battery must be fully charged before testing):
(under 100 Amp/Load test):     = Amp-Hour Capacity:
--------------------------------------         -----------------------------
          11.7 Volts                         21.0 Amp-Hours
          (=100% capacity: run vehicle no more than 100% range for max battery life)
          11.5 Volts                         20.0 Amp-Hours
           (=95% capacity: run vehicle no more than 87%  range for max battery life)
          11.3 Volts                         19.0 Amp-Hours
          (=90% capacity: run vehicle no more than 75% range for max battery life)
          11.1 Volts                         18.0 Amp-Hours
          (=85% capacity: run vehicle no more than 62% range for max battery life)
          10.9 Volts                         17.0 Amp-Hours
          (=80% capacity: run vehicle no more than 50% range for max battery life)
          (retire from electric vehicle)
          10.7 Volts                         16.0 Amp-Hours  
          10.5 Volts                         15.0 Amp-Hours
          10.3 Volts                         14.0 Amp-Hours
          10.2 Volts                         13.0 Amp-Hours
          10.0 Volts                         12.0 Amp-Hours
            9.8 Volts                         11.0 Amp-Hours
            9.6 Volts                         10.0 Amp-Hours
            9.4 Volts                           9.0 Amp-Hours
            9.2 Volts                           8.0 Amp-Hours
            9.0 Volts                           7.0 Amp-Hours
            8.8 Volts                           6.0 Amp-Hours
            8.6 Volts                           5.0 Amp-Hours (toss: recycle)
"Use it up,
 Wear it out,
 Make it do,
 Do without"
 -- from one of my mother's sampler-stitched pillows

This Amp meter is marketed and sold under a number of different brand names, by numerous retailers, but all are made by the same manufacturer (in China). Kragen Auto Parts, in fact, shipped an "EverSmart" model, while they advertised the unit as a "DHC Specialty" model. But the quality on all the units is excellent.

OEM Battery Charger for the HCF-305:

CTE Corporation Model# 4C24040 Battery Charger
120/240VAC/2A Input - 24VDC/5A Output

(click here to download CTE Corp. manufacturer's basic specifications)

(click here to download CTE Corp. manufacturer's detailed specifications)

Powering your HCF-305 with other types of batteries:

The HCF-305 comes equipped with small, compact sla-agm (sealed lead acid - absorbed glass mat) deep cycle batteries. The problem is that, while deep cycle, the standard issue WP20-24E batteries are not designed as "High-Rate" batteries, in that they are not designed to survive the heavy discharge demands of a 600 watt motor. 

But with the new breed of high-rate sealed lead acid batteries, there's really no better class of battery for the task. Sealed lead acid batteries first appeared in the 1970's, and have slowly improved and evolved into today's SLA's, which have twice the capacity, for their size, than those of the 1970's and 80's. SLA/AGM's are now a better choice than lithium-ion batteries. Even if not used, an electric vehicle, equipped with sla-agm batteries, will lose only about 8% of its battery charge, per month. And even that tapers off to only about 20%-30%, total, over a 6 month period. But breaking open and flooding the battery pack with electrolyte will cause the batteries to behave like typical flooded lead acid batteries, and battery pack will self-discharge almost 1% per day. 

Traditional flooded lead acid - deep cycle golf cart batteries are just too large and cumbersome.

Traditional flooded lead acid automotive batteries are not designed to survive the deep cycle applications required by electric powered vehicles. Using standard automotive batteries, in the HCF-305, will do permanent damage with each cycle, destroying them after about 25 run/charge cycles.

Deep cycle "marine" lead acid batteries (both flooded and absorbed gass mat) are not suitable for powering electric vehicles. Marine batteries have an internal design that is somewhere between that of a deep cycle golf cart lead acid battery and a traditional flooded lead acid automotive battery. The problem is that the initial performance will seem spectacularly successful  -until the battery pack finally dies after about 50 run/charge cycles. But, one real advantage of using marine batteries, is that the harbor masters, in many marinas, will freely give you their surplus used marine batteries. The batteries will work, but are just tired, and not up to full capacity. Not a bad deal for someone on the cheap.
Sealed lead acid - gel batteries are now making their way into electric powered "fun" vehicles. Sealed lead acid absorbed glass mat batteries are sometimes mislabeled "gelcells"  -which they're not, but creates to the confusion. But, like most compact sla-agm batteries, compact gel batteries cannot survive the rigors of 500 watt and 1,000 watt motors. And, more importantly, having an electrolyte in a gel state, they cannot be tampered with and effectively serviced by the handyman. Sla - gel batteries are, essentially, disposable batteries.

And don't be tempted to install a pair (or a four-pack) of readily available Fisher-Price Power Wheels 12 Volt, 9.5Ah batteries (wired in series) -or a pair Peg Perego 12 Volt, 12Ah batteries. Although a reliable, long-running power source for childrens' toy cars, these types were designed to handle only dual 20watt motors, geared down to run at 3 or 4 mph. Running these through a 600watt HCF-305 motor will quickly destroy them.

Nickel metal-hydride battery packs (made of multiple 1.2 Volt cells) are still too problematic for mobility scooter applications. So are nickel-cadmiums. And an electric vehicle, equipped with NiMH, or Ni-Cad batteries, if not used, will lose almost 10% of its battery charge, per day.
But keeping the electric vehicle plugged in on a low wattage float charge, when not in use, negates the discharge problems of such a battery pack.  And this is where a nickel metal-hydride battery pack could possibly shine.  Being smaller and lighter than lead acid batteries, a nickel metal-hydride battery pack could provide over 80% greater run time versus lead acid of the same size, due to its unusually flat, sustained operating voltage discharge characteristics.  This makes a nickel metal-hydride battery pack an excellent drop-in replacement, using the OEM electronic controller (even though it was programmed for lead acid battery pack).  However, a NiMH plug-in charger will be required to properly charge the new battery pack.  And an equivalent (24 Volts / 42 Amp-Hours) NiMH battery pack would cost as much as 10 times the price of a lead acid battery pack.          

Lithium-ion batteries are sometimes used in cost-is-no object projects, to appear high-tech and gain instant credibility. But in fact, the only "advantage" is that it would cost about an extra $ 1,000 American dollars to outfit your HCF-305 with a set of lithium-ion batteries, and they would still be the same size, same weight, and same 40 Amp capacity. But one little-known characteristic of Lithium-Ion batteries is that they just can't tolerate a fast discharge rate  -especially the demands generated by an electric vehicle.
Also, the OEM electronic controller on the HCF-305 would need to be replaced with a custom unit, since the lithium-ion battery pack voltage drops dramatically during normal discharge, and the OEM electronic controller, sensing a low voltage, would shut down the vehicle prematurely, with less range than the standard lead acid battery pack would produce.

The same applies to the new lithium-polymer batteries  -except that they do handle fast discharge rates quite well.
Fuel cell batteries, while promising, are too fragile, too expensive, and still under development for light electric vehicle applications. And even, if and when, they are developed and marketed, there is, at present, no infrastructure for readily fueling electric vehicles.

LiFePO4 (Lithium Iron Phosphate) battery technology just may change forever the light electric vehicle industry. The technology is here, and at a cost of only about 50% more the cost of an equivalent set of SLA batteries, the fate of lead acid batteries, for traction packs, is now sealed.  I have just installed a 25.6 Volt, 40 Amp-Hour LiFePO4 battery pack (ordered from Vpower, on ebay) in my HCF-305, and the results are phenomenal: The range is 50% more than my fine-tuned 24 Volt, 42 Amp-Hour SLA battery pack, and, at only 25 pounds weight, the LiFePO4 battery pack allows greater acceleration.  The entire package was $ 600.00, which included the battery pack, a 6 Amp 25.6 Volt fast charger, and one of the best battery Protection Circuit Modules on the market.  The 25.6 Volt battery pack is composed of 8 banks of parallel wired 3.2 Volt A123 18650 size LiFePO4 batteries, 36 batteries per bank, for a total of 288 batteries in the pack.  Internally, the battery pack is a maze of hot glue and wires.  I will eventually break the battery pack open, and rewire everything into a revised set of 8 banks, with the 288 batteries in removable holders, to allow routine testing and replacements.  I've found that the potential power loss, from a removable battery arrangement, to be more theoretical than real.  Stay posted.

LiFePo4 Battery Pack:

The development of truly new batteries for electric powered vehicles has been painfully slow and stubborn, with no real break-throughs in sight. False hopes have been generated by the fabulously successful lithium-polymer batteries, now used in many high-performance radio-controlled model race cars and model aircraft. But the transition of lithium-polymer power into electric powered vehicles has just not been cost-effective. And, quite frankly, not even effective.

So it appears that compact sealed lead acid absorbed glass mat batteries, with after-market electrolyte added, are the best bet for powering the HCF-305. With a 1:3 weight ratio (battery pack : total vehicle), this is what the good electric car of the future should be.
I've been tempted to re-fit my HCF-305 with two, switchable, 42 Amp Lithium-Iron battery packs (one main + one reserve), to double the range  -without increasing the weight, or overloading the electronic controller. But, quite frankly, am not willing to spend my time, driving my vehicle more than one hour, while doing local errands. A more provocative  -and fun, idea is investing the extra cash in a 24 Volt, 450 Watt wind generator and 110W solar panel combo, a $ 1,500.00 package that also includes tower hardware and an electronic charging panel (see "Green Power for the Light Electric Vehicle" web page).

Installing a new drive belt  -or a 5th wheel tire, on the HCF-305:
- The drive belt rarely completely snaps in two when it wears out. The vehicle usually comes to a complete stop, making a strange grinding sound as the weakened belt stretches and the small belt cog on the motor spins loosely against the cogs of the belt. Field service is just not practical for such repairs. The best option is to reach down, carefully cut the belt apart (easiest in the torn and damaged area of the belt), and completely remove it. The HCF-305, no longer hindered by resistance from the motor, can easily be pushed home (about as easy as pushing a bicycle, by the way).


- Using a 15mm box-end, or deep socket wrench, loosen both chrome round-head nuts on the left and right ends of the 5th wheel axle.
- Elevate both left and right rear wheels, by inserting a 3" brick under each wheel, allowing the 5th wheel to rotate freely, 3" off the floor.


- Locate the gloss black 5th wheel brake housing and mark  -or apply and fold over a piece of masking tape on the brake cable, just forward of the 10mm brake cable nut on the black housing. This simple step will greatly simplify re-assembly of the unit, after installing the new drive belt.


- Using a 10mm wrench, unscrew the brake cable nut on the black 5th wheel brake housing. The brake cable, under tension, will slip through the brake cable eyelet-bolt as the nut is loosened. Completely remove the 10mm nut and washer, and remove the brake cable eyelet-bolt from the black brake housing. Letting the brake cable hang loose, loosely thread the washer and 10mm nut back on to the eyelet-bolt, to keep everything in place and not lose anything.


- Using two 8mm wrenches, completely unscrew the bolt on the forward side of the black 5th wheel brake housing, rotate the black brake housing down, slightly, and hand screw (finger tight) the 8mm bolt, nut, and washer back into the black brake housing, to keep everything in place and not lose anything. The black 5th wheel brake housing is no longer anchored to the HCF-305 frame.


- Accessing from the rear of the HCF-305, using a 10mm wrench, unscrew and completely remove both 10mm lock-nuts from the 5th wheel belt tension adjustment bolts. Using a 10mm wrench, unscrew both 10mm 5th wheel belt tension adjustment nuts all the way to the ends of the 5th wheel belt tension adjustment bolts. The 5th wheel belt tension adjustment bolts, along with their "U"-shaped cross-section part, can be pulled off the rear of the 5th wheel hard-tail fork, completely removed off the 5th wheel axle, and set aside.
- Push the 5th wheel forward as much as possible, and reach up and slip the drive belt off the small belt cog, on the motor shaft.
- Completely remove both of the loosened 15mm chrome round-head nuts and lock-washers, by hand. Pull the 5th wheel and belt completely out of the hard-tail fork.
- This is the time to replace the tire of the 5th wheel  -if a tire replacement is the reason for the dissambly of the unit.

- There are 3 axle spacing collars, all are 19.5mm (25/32") outside diameter, that have to be replaced on the axle in the exact order:
  The 15/16"(24mm) long collar slips over the drive belt sprocket side of the 5th wheel axle.
  The 13/32"(10.5mm) long collar slips over the brake drum side of the 5th wheel axle.
  The gloss black 5th wheel brake housing slips onto the 5th wheel axle, over the brake drum and 13/32"(10.5mm) collar.
  The 1/2"(12.5mm) long collar slips over the brake drum side of the 5th wheel axle.
- Place the new drive belt on the large 5th wheel belt sprocket, and reinstall the wheel/axle back into the 5th wheel hard-tail fork, with all 3 axle collars positioned inside fork. Push the 5th wheel forward as much as possible. Reach in and carefully slip the drive belt into place on the small drive belt cog of the motor shaft. The drive belt may have slipped off the large 5th wheel sprocket and postitioned between the 5th wheel and large sprocket to provide enough belt slack to accomplish this.
- Pull the 5th wheel to the rear, making sure the new drive belt is seated on both the motor cog and 5th wheel sprocket.
- Re-install both 5th wheel belt tension adjustment bolts, along with their "U"-shaped cross-section part, on the 5th wheel axle. The "washer" part of the belt tension adjustment bolts mounts on the axle and lays absolutely flat against the hard-tail fork, but the long tension adjustment bolt needs to be carefully oriented so that the bolt curves towards the 5th wheel and nests within the narrow channel, in the arm of the fork, and mates perfectly through the "U"-shaped cross-section part, which seats neatly on the rear end of the hard-tail fork.
- With both of the 5th wheel belt tension adjustment bolts, along with their "U"-shaped cross-section parts in place, hand screw both 10mm 5th wheel belt tension adjustment nuts all the way to the "U"-shaped cross-section parts, as they begin to snug against the rear ends of the ends of the 5th wheel hard-tail fork.
- Install both 15mm chrome round-head nuts and lock-washers, on the 5th wheel axel by hand. Leave loose, not tight. The 5th wheel axle needs to shift forward and backwards, without resistance, for the drive belt adjustment (listed below) to work properly.
- Rotate the black 5th wheel brake housing into position, so that the 8mm bolt slot on the frame lines up with the 8mm bolt slot on the black 5th wheel brake housing. Insert the 8mm bolt into the slot and finger tight the washer and 8mm nut on the other side. Using two 8mm wrenches, carefully screw the bolt and nut together, but not snug.
  The point to make here is that the black 5th wheel brake housing will have to properly oriented  -yet slide easily backwards and forwards on the HCF-305 frame, as the drive belt is carefully adjusted. The reason for doing this is that the brake housing cannot be rotated after the 15mm chrome round-head nuts are finally tightened (as described below).
- Using a 10mm wrench, carefully tighten the drive belt side of the 5th wheel belt tension adjustment bolt. The drive belt will slowly begin to tighten. Periodically loosen the 5th wheel belt tension adjustment bolt, on the brake drum side, as the drive belt tension adjustment progresses, as this side must remain slack, as the drive belt is tightened.
- The drive belt needs to be taught, -but not too taught. The OEM HCF-305 drive belt (Optibelt Omega 825-5M-A) should be stretched taught enough, to the point that firm thumb pressure (6lbs or 2.7 kilograms) at the outside-middle span of the belt, between the cogs, deflects the belt 4mm (5/32") -but not tighter.
- Another way to set the drive belt to the proper tension is to tighten the belt until the distance between motor shaft and the 5th wheel axle is 22.1cm (8-23/32"), on center. To accurately and easily judge this, a thin wooden jig can be fashioned, with an inside span of 23.5cm (9-1/4"), to box in both the 19.5mm (25/32") diameter collar over the 5th wheel shaft, and the 10.5mm (13/32") diameter flanged nut on the end of the motor cog. The drive belt is then carefully tightened until there is no back-and-forth play along the length of the wooden jig.
- Another way to get a "feel" for the proper drive belt tension is to squeeze and tug at the drive belt, as installed at the factory, BEFORE you ever need to change the belt. The OEM drive belt, as set at the factory, when held at mid-point, between the thumb and forefinger, will allow the belt to be twisted about 1/8th of a turn, but don't force it, as the belt was not designed to take such stresses. The drive belt, by its nature, cannot stretch. So too much tension will destroy the belt, as well as damage the bearings of the motor and 5th wheel.
The Optibelt Omega 825-5M-A (actually designed as a timing belt) is made of a highly stable composition of chloroprene, reinforced with high-strength glass fiber tension cords, which produces a tough belt that, due to its nature, is simply not designed to allow  -or survive, being stretched.

(click photo for a much larger, detailed picture)

- To ensure a long life with the drive belt, the motor shaft and the 5th drive wheel axle must be adjusted parallel to each other, and the belt cog wheels on the motor shaft and 5th wheel must line up with each other, with the drive belt 90 degrees to the shaft and axle. This adjustment is done as follows:  As the drive belt arrives at the proper degree of tension, align a straight edge flush against the smooth face of the 5th wheel drive belt sprocket, and check to see if it lines up to the right edge (when viewed from the rear) of the thick washer on the drive belt cog on the motor shaft (held in place by a screw on the end of the motor shaft).  Generally, it will not line up, as the straight edge on the 5th wheel sprocket will initially point to the left of the desired position on the motor cog.  When properly adjusted, the drive belt will snug up to the left edge (when viewed from the rear) of the drive belt cog of the motor. 
- Continue tightening the 5th wheel belt tension adjustment, on the belt sprocket side, occasionally checking that the 10mm nut on the brake drum side of the 5th wheel belt tension adjustment bolt stays loose at all times, loosening it when necessary. As the 5th wheel belt tension adjustment nut, on the belt sprocket side, is tightened, the straight edge will slowly creep to the right, into the proper position. This is when the tightening of the brake drum side of the 5th wheel belt tension adjustment bolt begins.


- Using light finger pressure only, screw in both left and right 15mm chrome round-head nuts on the 5th wheel axle. This will keep the motor shaft cog and the 5th wheel sprocket in line with each other. Both 15mm nuts must remain loose enough to allow the 5th wheel axle to freely move forwards and backwards during the drive belt tightening process.  
- Continue holding the straight edge against the 5th wheel drive belt sprocket, but tightening the 10mm nut on the brake drum side of the 5th wheel belt tension adjustment bolt.
- Check the drive belt tension to make sure that it's not too tight, while also making sure the 5th wheel axle are still parallel to the the motor shaft, and motor belt cog and 5th wheel sprocket are lined up with each other. This is a critical part of the process  -but well worth the effort.      


- This adjustment done, tighten down both 15mm chrome round-head nuts (and lock-washers), with a wrench, on the 5th wheel axel, alternating back and forth, until both are tight and snug. This method will disturb the drive belt alignment the least.


- Using a 10mm wrench, install  and snug down both 10mm lock-nuts on both 5th wheel belt tension adjustment bolts.
- Re-check the motor cog and 5th wheel sprocket alignment with the straight edge, as well as the drive belt tension.
- By hand, give the 5th wheel a good spin, and check that the drive belt seats properly on the 5th wheel sprocket. Then spin the 5th wheel in the opposite direction and again check the drive belt alignment. A properly aligned drive belt will snug against the raised right edge of the 5th wheel sprocket, when spinned in one direction, and will remain snugged to the raised right edge of the 5th wheel sprocket, when spinned in the opposite direction.  But don't hesitate to loosen up and re-do the drive belt adjustment process over again, if something doesn't seem right.
- Using two 8mm wrenches, completely tighten the nut bolt on the forward side of the black 5th wheel brake housing.


- The brake cable can now be re-installed. Unscrew and remove the nut and washer from the brake cable eyelet-bolt. Insert the brake cable eyelet-bolt (with the brake cable threaded) through the brake shoe lever. Slip the washer onto the bolt, from the right side, and screw the 10mm lock-nut into position on the bolt. Pull the brake cable through the brake cable eyelet-bolt until the masking tape lines up to the bolt head, and tighten the 10mm lock-nut.
- Spin the 5th wheel by hand, to make sure that the brake does not bind and the wheel spins freely. Spin the 5th wheel again and apply the brake (on the operator's left-front handlebar) to make sure the brake functions are quick and sure.
- Roll the HCF-305 off the 3" blocks and onto a flat surface. Check the 3 rear wheels. If one, or both, of the rear side wheels spin freely, then the drive belt tension is probably too tight and needs to be loosened and re-adjusted until both rear side wheels are more or less level with the 5th wheel.
- Give the vehicle a quick test run, re-checking everything afterwards.
- Unusually loud drive belt noise, along with sluggish acceleration and slow cruising speed while driving, is an indication of the belt tension being too tight. The Optibelt Omega drive belt was designed with a shallow groove, 20mm long, along the gear side of each tooth, just to make the belt to run quiet. And obvious belt noise is a sure indication of trouble that should be immediately corrected.
- One's first experience with drive belt installation and adjustment is always tedious and sometimes frustrating, but subsequent maintenance will only go faster, with expert results. 


ZX899920U Wiper Motor + ZX818809Y Wiper Arm + Trico "Exact Fit" blade # TRICO 11-1

Windshield Wiper for the HCF-305:
I've just installed a windshield wiper system on my HCF-305. Weighing in at only 1-1/2 pounds, the single-speed, non-self parking 24 Volt motor wipes the curved windshield @ 1.05 cycles per second (= 1 wipe across the windshield every 0.525 seconds), the 6mm diameter motor shaft covers a 90 degree sweep. Maximum current draw is about 2 amps (= 48 watts), at peak load.
Cost was $29.99 U.S. dollars + shipping.
To order to order the windshield wiper motor, here's the link to the J.C.Whitney website:
Be sure to order Catalog Item# ZX899920U Windshield Wiper Motor 24-Volt.
The motor housing is not waterproof, nor water-resistant, and should only be mounted in interior locations.
It's a good idea to take apart the wiper motor and carefully re-distribute the gear grease over the gears. Be sure to remove the 6mm wiper shaft, from its threaded sleeve, and cover it with a liberal coating of the same grease, as the 6mm wiper shaft is, oddly, not lubricated. Also, the 90 degree sweep of the 6mm wiper shaft can easily be changed to a 110 degree sweep, if desired, simply by re-inserting the 6mm wiper shaft pin into the other hole of the final gear.
The black rubber sleeve, on the end of the 6mm motor shaft and threaded sleeve, should also get a good application of plumbers grease, between the 6mm shaft and the rubber sleeve, as well as between the rubber sleeve and the wiper arm nut.   
The motor is also known as Model# TMC-006 windshield wiper motor, as sold by other retailers, and should be wired in with a 24 Volt, 1-2 amp fuse.
Windshield wiper motor must be used with the J.C.Whitney stainless steel arm, available separately (see below).

Schematic showing dimensions of the wiper motor:
JC Whitney ZX899920U Windshield Wiper Motor 24-Volt

Windshield wiper arm for the J.C.Whitney wiper motor:
The wiper motor has a 6mm shaft, and the only wiper arm that will fit is also sold by J.C.Whitney.
Cost was $9.99 U.S. dollars + shipping
Order Catalog Item# ZX818809Y, at the below link:
JC Whitney ZX818809Y Windshield Wiper Arm & Blade 11" is the catalog description.
There is confusion in their website, in that a photo of the item shows a picture of a curved windshield wiper blade only (and NO wiper arm!)  -and not the type of blade that they will ship you.
The catalog item is actually an adjustable stainless steel blade arm, that allows a custom 13-3/8" to 17-1/2" motor pivot-to-end of blade sweep. The wiper arm has a bayonet mount slip-on style, and not the hook style (see photo, above). Also included is a simple, squeegee type of blade that works only on flat windshields  -and should be simply tossed, as it's not very good  -even on flat windshields.
The wiper arm tightens onto the 6mm windshield wiper motor shaft with a 10mm wrench. 
Windshield wiper blade for the J.C.Whitney wiper arm:
I purchased, from Kragen Auto Parts, a standard Trico "Exact Fit" series, blade # TRICO 11-1 (see photo, above).
The blade has fittings to easily attach to a wiper arm, and has a bayonet mount slip-on style (as well as the standard hook style). 
Cost was $ 9.00 U.S. dollars.

Details About the HCF-305 Motor and Belt Drive:

HCF-305 Motor Specifications:
Manufactured 11-30-2004
Carbon-brush motor: 4 brushes.
Output: 13 Watts - 600 Watts
Weight: about 7 pounds.
Voltage: Operating Range: 15~32Volts DC
             Nominal: 24Volts constant
No Load RPM: 3,700rpm
          Current: 2A
Nominal RPM (Maximum Efficiency): 3,270rpm
                                          Current: 9A
                                           Torque: (info to follow)
                                            Watts: 216
Maximum Operating Temperature: 150 degrees Fahrenheit
In normal drive mode, motor turns clockwise, when viewed from shaft end.
Motor shaft diameter: 11.5mm (7/16")
Motor Diameter: 99mm (3-15/16") *** Motor mount is a snug fit: 4" maximum diameter for alternate/substitute motor.
Motor Length:  111mm (4-3/8")  + shaft = 152mm (6")
Motor mounts: ISO M6 x 15mm, 1.00 pitch, button head (requires 4mm hex key), 4 mounting screws: 60mm (2-3/8") on center.
Usable machine screw length 3/8" max. from motor mounting surface.
Drive Belt: Optibelt Omega 825 5M-A (1 tooth per 5mm). *** Non-standard 20mm wide belt. The closest standard stocking width is 25mm, which is too wide for the HCF-305 drive gears. But, being made in Germany, this standard HCF-305 factory issue part is of excellent quality. 
1:9 gear reduction ratio:
Motor Gear: 14 tooth 5M, 31/32" outer diameter (measured with belt in place). *** Non-standard: for 20mm wide belt. *** Motor gear is not removable: Motor shaft was probably shrunk at the factory, with liquid nitrogen, and then inserted into the Motor Gear, to warm up to ambient temperature and expand into a tight fit.
5th Wheel Gear: 126 tooth 5M, 7-15/16" outer diameter (measured with belt in place), 3 set screws, 32mm on center (from axle). *** Non-standard: for 20mm wide belt.
5th Wheel Axle Fork: 140mm (5-1/2") inside span, for 10mm (13/32") axle. Fork is welded to the vehicle frame, as a non-adjustable hardtail.
The motor of the HCF-305, when powered at full speed, by a good, high-rate discharge battery system, will run hot to the touch. This is completely normal with most electric bicycle and scooter motors, and will not damage the HCF-305 motor. And when the internal temperature of the motor does approach "red-line" temperatures (above 150 degrees Fahrenheit), the internal thermal overload sensor, inside the aluminum end plate of the motor, signals a microprocessor, in the electronic controller, which trips out the circuit breaker, causing the circuit breaker button to pop out to its fully extended position, stopping the vehicle.
This is normal. Simply allow the motor to cool, for about 20 minutes, then reset the circuit breaker by pushing in the button. The HCF-305 will operate normally again. An over-heated motor rarely causes the HCF-305 to shut down, unless it's run hard, at full speed, for an unusually extended period of time (over 4-1/2 miles). In normal use, where the HCF-305 is driven to a destination (even at maximum speed), parked, shopping done, and the vehicle driven back home  -or to yet another destination, the motor has the opportunity to cool off, and rarely reaches an over-heated condition.
Worn out graphite brushes are replaceable, with many hardware stores stocking assorted sizes. The HCF-305 graphite brushes wear away at the rate of about 1/16 inches (1.6mm) every 1,000 miles (1,610 kilometers) and have an expected life of about 3,000 - 4,000 miles (4,830 - 6,440 kilometers) before needing to be replaced. The 30mm diameter rotor-commutator has, so far, shown no signs of wear. Also, once a year (or 1,000 miles / 1,610 kilometers), it's a good idea to remove and open up the motor, and give the insides a good blast of air to remove the ashes generated by the normal wearing of the carbon brushes. When re-installing, the motor should also be rotated and mounted 180 degrees, out of the previous posiion, to distribute wear on the unused portions of the sealed bearings.  

14 tooth 5M x 20mm wide belt gear on motor shaft

DC Motor Commutator

4 carbon brushes


Internal thermal overload sensor: A sensor with separate leads, NOT wired in to the motor.

Rejuvenating the OEM HCF-305 24Volt batteries?

Standard HCF-305 WP20-24E Battery

(click here to download WP20-24E manufacturer's specifications)

Battery Specifications:  
Brand:            Long
Manufacturer: Kung Long Batteries Industrial Company, Limited, Taiwan
Model#:         WP20-24E
Capacity:      24V / 20 Ah sealed lead acid 
Dimensions:  Each battery is 5-3/4" wide x 7" long x 6-1/2" tall
Weight:         26.95# per battery x2 = 53.9# total

The two batteries are factory installed, parallel wired, producing a 24V / 40 Ah power source, that is charged @ 24V and enters the electrical system of the vehicle, via the Controller, as 24V.
One important part of the initial setup of the HCF-305 is to place the two thick cushion pads, that came installed on top of the batteries,under the batteries. Completely remove the batteries from their compartment and place the cushion pads on the compartment floor. The pads serve no useful purpose on top of the batteries, but underneath, will cushion the batteries from shock and vibration, transmitted from the power wheel (5th wheel), through the hard tail, directly to the frame that holds the batteries.
Another important step, when you uncrate your brand new HCF-305, is to break open the "sealed" batteries and add a standard battery electrolyte solution into the cells. This is probably the only modification to the OEM battery pack that will work. Read on.
The problem with the batteries of the HCF-305 is that they are simply not designed to cruise at 12mph, with a 600 watt motor, for any length of time. The HCF-305, like many electric powered "fun" vehicles, is powered by compact and lightweight sealed lead acid batteries (sla's for short) that, while are deep cycle, are not true fast discharge batteries. In short, the batteries will quickly deplete their electrolyte after several test runs, 5 to 7 miles each, on a flat, level, paved surface, for about 25 to 30 total miles.
And I mean dead. Sure, the batteries will register 24 Volts on a volt-ohmmeter, but there will be no life left, even if fully charged. If the 5th wheel (the drive wheel) is elevated above the pavement, a dead set of batteries will still turn the wheel, but the torque just isn't there. These are the classic symptoms of sealed lead acid batteries which have been "cooked" by a 600 watt motor.
Unfortunately, these symptoms can combine to thoroughy baffle the handyman, who will erroneously conclude that the batteries are good, and then waste time and energy testing the HCF-305 battery charger, or the HCF-305 Electronic Controller, or the 600 watt HCF-305 motor.
Various attempts to rejuvenate these compact, lightweight, and over-worked batteries, but nothing works.
I caution you that my efforts to rejuvenate the OEM batteries have not been successful. And the battery experts warn that there is no safe and effective way to get the water (or electrolyte) back into the glass mats, inside the cells. In fact, I tampered with the old batteries about once a month, for almost a year, but with no results.
The original battery pack(s) has been replaced with a set of 4 - 12 Volt PowerSonic batteries, as I was eager to get the HCF-305 fully operational and on the road. Attempting to save sla's is time consuming work and, from what I've found on the internet, the results, at best, are mixed, commonly with a reported low recovery rate of about 15%. And even then, the batteries become unreliable and may still require high maintenance.
Classified as "sla agm" batteries, the HCF-305 batteries are sealed lead acid batteries with absorbed glass mat baffles between the lead plates. The purpose of the glass mats is to contain the electrolyte (battery acid and water), so as not to spill out, if and when the battery is turned on its side, or upside down.
That's fine for powering burgler alarms, computer backup power supplies, etc., but not for fast discharge applications (aka "traction packs"), such as motorized vehicles.
And you're not going to turn your modified batteries upside-down  -are you?
The sealed lead acid batteries of the HCF-305 are equipped with simple one-way valves (rubber caps) that allow gases internally generated by the battery to vent off, in a controlled manner. The problem is that these one-way valves create a vacuum inside the battery that wicks the electrolyte out of the glass mats, as the over-worked battery cools back to ambient temperature.
To remedy this condition, the battery must be opened and standard battery electrolyte added the the cells.
Also, the one-way valve caps can be made more functional if they are punctured with a simple push pin, producing a small hole, just enough to allow gases in the battery to freely pass back and forth, eliminating the temporary vacuum that seems to be drying the glass mats out. The electrolyte will now last longer, without needing regular topping off with distilled water. 
The sla batteries of the HCF-305 are similar to deep cycle marine batteries and golf cart batteries, in that they require the same battery electrolyte: sulphuric acid pre-mixed in water, available over-the-counter in many auto parts stores.
Gently pry open the plastic battery covers with a sharp knife and remove the black rubber caps (valves). Wearing eye protection, latex gloves, and using an eyedropper, carefully add about 16 fluid ounces (.4732 liters) of electrolyte to each 24 Volt battery. Forcefully squirt the electrolyte into the battery cell, so as not allow it to flood outside, on top ot the battery, making a hazardous mess.
Do this until the dry glass mats and lead plates remain slightly covered covered with the electrolyte. But this won't work on batteries that are already "cooked". The glass matts are designed to hold their electrolyte, even when turned upside-down and, likewise, damaged, dried-out glass mats will resist absorbing new electrolyte that is introduced into the battery.
As electrolyte is added to the battery cells, remove any bubbles that may have formed in the cap openings, with a plastic straw, and carefully check the fluid level with a small, single led light, while in a darkened room or shed.
The next step is to replace the batteries back in the HCF-305, and completely recharge them.
Hook up the charger to the HCF-305 and give it a good 12-14 hour charge cycle.
After logging on 50 miles or so, remove the batteries from the HCF-305, open them up, and top the cells with more battery electrolyte, if needed.
Carefully replace the flat black plastic tops over the rubber cap valves, and seal with a good, clear scotch tape, taking care not the seal the outer vent holes at the ends.
Note: From now on, periodically inspect the cells and top off, if needed, with battery electrolyte solution.
"Sulfating" in Sealed Lead Acid Batteries:
Now that you have converted your HCF-305 batteries from sla-agm (standard sealed lead acid with absorbed glass mat baffles) into true high discharge - deep cycle batteries with fla (flooded lead acid) characteristics, much like those used in lake fishing boats, golf carts, and industrial fork-lifts, we can now enter the next phase of battery rejuvenation. 
Sulfating is the main cause of failure in sealed lead acid batteries. Lead-sulfate is formed due to chemical reaction between the lead plates and the sulfuric acid during the normal discharge of a lead acid battery.
And it's not just the HCF-305 mobility scooter that has serious battery issues: Almost all of the small electric toy and sport scooters experience premature battery failure. Running a 500 watt  -and especially a 1,000 watt motor, on relatively small, compact sealed lead acid - absorbed glass matt, or small sealed lead acid - gel batteries, quickly evaporates the battery electrolyte through the one-way valves, and the lead plates become coated with lead-sulfate deposits. As a result, the retailers and online suppliers do a brisk, repeat business of selling replacement batteries  -and with a re-order frequency not unlike the printer inkjet cartridge business.
What is an "Electronic Desulfator Device"? 
Unlike the large, expensive commercial units, the home version is basically a small, inexpensive device that electronically dissolves sulfating formations, on the lead plates, back into the electrolyte solution, without taking the battery out of service. Operating on the 24 Volt power of the batteries themselves, the unit dissolves sulfate crystals back into the battery’s electrolyte solution, causing a reversal of sulfating accumulation in the existing batteries, and also prevents sulfating formation in new batteries.
The commercial versions do this overnight, the home unit will require a week or two to restore the battery. A good, effective off-brand unit can be purchased on ebay for about $ 25.00 American dollars.
The unit creates weak but sharp electrical pulses, that are injected at a frequency which is equivalent to the resonant frequency of the sulfate crystals, with a fast voltage rise and short duration of direct current. As a sulfate crystal resonates, it is able to become ionized and reform back into the electrolyte as an active material. Gently dissolving the sulfate coating without damaging the electrode plates, the battery plates stay clean, providing more power, faster recharge speed, and cooler charging temperatures.
There have been questions raised by those who doubt the effectiveness electronic desulfators. But the fact of the matter is that they have long been an indespensible device, that was in common usage in American submarines, during world war II. Periodic desulfation of the vast battery pack was a routine part of submarine maintenance. So powerful were these onboard desulfators, that the 10,000 cycles-per-second "hum", from deep inside the batteries, could be heard throughout the submarine. 
But the installation of my tiny electronic desulphator is quick and simple: Having only two wires (one black and one red), it attaches to the battery posts. The HCF-305 can be operated and charged, with the unit in place, but not recommended for the HCF-305, since the unit draws 480mw of current and will discharge the batteries. In fact, after a day or two of de-sulfating, the HCF-305 will need to be recharged before using.

Typical home electronic desulfator device:
(click photo to go to the manufacturer's website)