I designed and built this fun and successful light electric vehicle several years ago. I'm just now posting it on "Instructables" and will add more steps, detailing the construction, in the next few weeks.

Use the link to my webspace, for the details, for the time being:


I decided to build an electric vehicle from off-the-shelf components, using existing technology. The goal was to define auto transportation, down to the basic motor vehicle errand: One passenger plus a sizeable payload, to and from destinations of up to 5-10 miles away, rapidly, all at an affordable price.

And electric mobility scooters, unlike most electric automobiles, seemed to already be on the right track -they just needed to run faster. And, after checking the mobility scooters on the market, the HCF-305 seemed uniquely suited for the project. It actually ran so fast that it got the manufacturer in trouble and the medical mobility vendors quickly unloaded their HCF-305 inventories. And I knew that this vehicle would be perfect for the task.

I began to modify the HCF-305, by first installing an ultralight aircraft seat and harness for comfort, stability, and protection, and then building up the body around it.

This homemade vehicle is classified as a "Light Electric Vehicle": A new breed of efficient, lean-and-mean machines that weigh little more than the passenger(s). The Light Electric Vehicle is powered transportation distilled to its essence.

The issue with most electric vehicles these days is that they often weigh in at 2,500 pounds or more. And such a vehicle has the daunting obstacle of simply transporting itself, which is, at best, a losing battle.

Another uncomfortable truth is that full size electric vehicles put a strain on the local electric power grid: Most communities do not have the electric power infrastructure, specifically, neighborhood power lines and transformers, to properly charge more than one or two full size electric vehicles per neighborhood.

Now, I have 3,000 miles (360 charge cycles) logged on this vehicle. Everywhere I drive this odd duck people approach me, wanting to buy one. I politely tell them that I would starve if I made these things for a living.

This project is not unlike my radio control model aircraft: It's a true labor of love -that requires a considerable amount of research and tinkering to keep everything running smoothly. But the casual bystander only sees a cute, reliable vehicle that quickly and effortlessly runs errands all over town. And it would be a quite a stretch to assume that this vehicle is anywhere near ready for the mass market.

Like many members in my local Electric Automobile Association, I see my electric vehicle as a toy and a joy, and certainly not yet a viable substitute for an internal combustion engine vehicle.

But we try.
omoralde9 months ago


omoralde9 months ago


Edgar1 year ago

Nice! :)

Favorited, Downloaded, and Blogged, so a lot of folks will build this neat car of yours, all over the World:


jrjohnwood2 years ago
I have been following your battery upgrade and wish to ask how are they performing now? I am getting ready to order 4 very similar style of AGM SLA batteries to use on a front wheel 1000 watt bike motor, but since you have the ONLY post of adding extra electrolyte and bypass the pressure check valve by pin pricking the cell caps, I am concerned to their longevity. Would sure hate to crater a brand new set of batteries, you know. Just wondering is all, and congrats on a really nifty setup!
shastalore (author)  jrjohnwood1 year ago

jrjohnwood: I apologize for the delay, but your comment was buried in a secondary page of my instructable, and I just saw it. My 24VDC, 40 amp-hour flooded sealed lead-acid battery pack will function for about 150 charge cycles = about $ 0.15 per mile for battery pack expense. In comparison, my same 1-passenger electric vehicle cost about $ 0.25 per mile tire wear expense.

As for the longevity of the batteries: After being retired from my electric vehicle (at 80% capacity = 50% range) they still have years of use with my portable homemade wind generator and portable homemade sun tracking solar panel. I periodically do a 12 Volt Amp-Load test on each old battery and reference a chart to assign each battery a revised (and lower) Amp-Hour rating, just to always know the useful capacity of each battery.

As for running your 1,000 Watt motor with a 24 Volt, 40-42 Amp-Hour battery pack, it'll probably overload your battery pack, even if flooded and electronic balancing modules added to the batteries. You'll probably need a 24 Volt, 70 Amp-Hour battery pack. But you never stated the rated Voltage of your 1,000 Watt motor, so I'm just guessing.

shastalore (author)  jrjohnwood2 years ago
My flooded (and pin-pricked cell caps), and electronically balanced, AGM-SLA batteries worked exceptionally well, and I eventually retired them in favor of a LiFePO4 replacement battery pack.

But these retired, old lead-acid batteries are still more than welcome with my portable wind generator and portable solar panel applications, for years of use. That's the long-term advantage of flooding AGM-SLA batteries.

So don't worry that you would "crater" a brand new set of batteries. AGM-SLA batteries are already "electrolyte-starved," that is, the AGMs are 99% full of electrolyte, so simply filling the empty air spaces in the battery cells with standard electrolyte solution will not any damage what so ever.

Granted, I'm the ONLY post on the internet advocating breaking open and flooding AGM-SLA batteries (and voiding the warranty), but I'm also the only post on the internet in numerous, diverse applications, not hesitating to point out the flaws in many main-stream, but unexamined, beliefs, and providing my own detailed, tried-and-proven solutions.

But I really want to point out that I am no longer an advocate of lead-acid batteries, for electric vehicles. A LiFePO4 battery pack, that will fit snugly into your existing battery compartment, will weigh half as much as your present lead-acid battery pack, will provide 3 to 4 times the range of the lead-acid batteries, and will last at least 4 times longer than the OEM lead-acid battery pack, if not more.

I purchased my 24-Volt, 40-Amp-Hour LiFePO4 battery pack, from V-Power, on ebay, several years ago, and, amazingly, it shows absolutely no signs of decline. And am so satisfied with it that I no longer advocate lead-acid batteries for electric vehicles.

souixzan2 years ago
i have a zap xebra under the flat bed zap has 7 12 volt batteries
that are wired in two series. in order for the charge
to be evenly distributed it used a powercheq pchq-12v-2a.
these little boxes with three wires + and - and ground
are bi-directional and equalize the charge so that none
are over or undercharged. this circuit has been broken
and the batteries now read: dead, overcharged, dead, overcharged, et al.
everything worked well before this cycle was broken.
now, all i really need is another of these little boxes (or similar component)
to re-complete the cycle. can u help? i cannot find these powercheq's anywhere
- the company who used to manufacture them stopped making them 4 years ago.
thanx so much for your time and consideration i am learning as i go and glad of it!
suzia aufderheide
ashland, oregon
shastalore (author)  souixzan2 years ago
Hello Suzia,
The PowerCheq modules were designed for electric wheelchairs, for 12-Volt 21-Amp-Hour maximum size batteries.
Unfortunately, many full-size electric vehicle owners have installed these PowerCheq modules on their 12-Volt 100-Amp-Hour batteries, and are frustrated to discover that there is very little difference in performance.
But a quick glance at the thin wires on the PowerCheq modules, compared to the heavy, gnarly 12-Volt battery cables, should make it obvious that those tiny modules can't possibly transfer or divert enough current to keep their battery pack balanced.
And I don't know of any tried and proven, high capacity electronic modules on the market to suggest for 100-Amp-Hour batteries.
But to install a new lead-acid battery pack will cost you about $1,500 to $2,500, depending on the brand and type, and that's not including labor. And that does not include essential electronic battery balancing modules between each battery.

What I do suggest is that you check out ebay, and search for LiFePO4 battery packs, although you will probably not find 72-Volt battery packs. But contact some of the highly rated vendors and approach them about the possibility of one of their staff engineers putting together a custom LiFePO4 replacement battery pack, complete with charger and electronic battery balancing module, for your Zap Xebra. The advantage here is that the Zap Xebra OEM electronic controller will not have to be reprogrammed for the LiFePO4 battery pack.
Their price for all this may shock you, until you revisit the true costs of a lead-acid battery pack.

A LiFePO4 battery pack, that will fit snugly into your Zap Xebra battery compartments, will weigh half as much as your OEM lead-acid battery pack, will provide 3 to 4 times the range of the OEM lead-acid batteries, and will last at least 4 times longer than the OEM lead-acid battery pack, if not more.

I purchased my 24-Volt, 40-Amp-Hour LiFePO4 battery pack, from V-Power, on ebay, several years ago, and am so satisfied with it that I no longer advocate lead-acid batteries for electric vehicles.
quote "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"
why will this burn out the controller? i thought it would just add range as the controller will only draw the amps it needs as if this were true then replacing a 2c lifepo4 battery with a 10c battery would this not cause the same damage?
shastalore (author)  oldskoolhead2 years ago
Electronic controllers are rated, and chosen, on a number of factors, such as to the maximum Amp-Hr battery pack they are designed handle.

And the OEM HCF-305 electronic controller is not exactly a heavyweight in this arena. To further illustrate, you may have noticed that kids electric scooters have much smaller controllers, while electric motorcycles have much larger controllers -designed to handle much larger battery packs and loads (motors).

A few HCF-305 owners have emailed me to complain that their high performance mobility scooter no longer works. And after reviewing their list of symptoms, a custom, oversize battery pack is often the culprit (such as a 80 Amp-Hour pack). And these unique OEM controllers need to be especially valued, since they are becoming more difficult to replace, as they handle numerous automatic functions throughout the vehicle, besides the basic speed controller functions of the 24V electric motor.

The electronic controller mentioned in this article is not re-programmable, although one HCF-305 owner is attempting to do just that, but I haven't heard anymore from him in over two years. The main barrier to this is that the internal circuit board of the OEM device is injected, at the factory, with a super-tough glue that resists any attempts to chemically dissolve it, and open the circuit board for tampering.
Thanks for the great write up and advice clearly you did your homework and it paid off!
FrozenIce3 years ago
way too many words on one page...
M0HIZ FrozenIce3 years ago
epierce3 years ago
Thanks for the info Shastalore! My solar charged trike has done 1000 miles in 10 months but has had to be charged old school style lately.
12 volt lead acid batteries don't top out at 12.6 volts, or even all that close really. They actually top out at 13.8-14.2 volts(when newer of course)This extra voltage used to be called "float voltage"(not sure if they have a new name fir it now or not) But to get rid of that
'float charge" just run the lights for a few seconds-1 minute. then you will be back to "normal full charge.

Also heat affects batteries very little nowadays, unless you have a battery installed in a hot or cold climate and then move to the opposite climate. Batteries like gasoline are designed for the normal outside temperature they are expected to run at.(example)batteries made for use in very hot vlimstes have fewer plates that are thicker, this allows the lead to withstand the extreme heat better but reduces the cca's. Batteries made for extremely cold climates have thinner but more plates increases the cca's but causing no problem with lead deformation due to cooler temps. You wanna see a battery die in a real hurry? Buy one from a desert location and then move to a place like new york, or vice versa.

I found a good explanation of the effects of temps on battery life on the net and will repost it here.

"Battery capacity (how many amp-hours it can hold) is reduced as temperature goes down, and increased as temperature goes up.
Even though battery capacity at high temperatures is higher, battery life is shortened. Battery capacity is reduced by 50% at -22 degrees F - but battery LIFE increases by about 60%. Battery life is reduced at higher temperatures - for every 15 degrees F over 77, battery life is cut in half"

Now this is usually not a real problem since the effects on batters are not a one shot deal. In other words if your battery spends 6 months a year at -22F you gain a 60% increase in battery life.But if you spend the other 6 months of the year around 100 degrees you will lose about 60% of battery life, however it will average out and the battery will last about the same as if it was at 77 Degrees all year long.
lobo0x76 years ago
wow shastalore! i am amazed of your deeep knwoledge on batteries. good work, thanks for sharing i am trying to put together some sort of e-vehicle and you are the number one in my list of batterie gurus... can i make you a couple of questions? one is: does it matters to mix diferents sizes (amps) of batteries as far as de volts are the same? and diferents voltajes? the second one is a bit more general: wich configurationn will you recomend for a ultralight e-motorcicle (or a heavy bike) in order to have the better range possible (it will be used mostly in town and in small road trips, so hi-speed is not a must)? i meant basically motor? watts? volts? (i still thinking in mantain the pedals like in a bike specially for avoid the motorcicle treatment by the road police), so, hub motor? and wich batteries do you recomend in order to have decent range without beeing screwd by the prices of high.tec batteries? it was a lot more than 2 questions, after all thanks again
shastalore (author)  lobo0x76 years ago
The batteries in your electric vehicle should be a matched pack. That is, order the batteries you need at the same time. All should be the same size and capacity. And, after receiving the shipment, be sure to fully charge, and then test each individual battery with an amp / load test. A simple $ 30.00 amp / load test meter can be purchased at your local auto parts supplier. Check out my webspace link for the details of using this device, as documentation and technical info is notoriously absent with these inexpensive devices. And such an amp / load test will destroy a small SLA/AGM battery. A good rule of thumb is that 1 out of 10 (1 out of 12, in my experience) sealed lead acid batteries, from the factory, will amp / load test as "bad", or defective. I'm an advocate of high-rate, sealed lead acid, absorbed glass mat batteries, for light electric vehicles. They are very tolerant of misuse and abuse. Other more exotic batteries are fraught with problems that the new experimenter is ill-prepared to finance, problem-solve, and achieve satisfactory performance. As you seem to just be starting into experimentation with light electric vehicles (welcome aboard) I would suggest that you purchase a basic electric conversion kit (rear wheel/brushless motor hub, battery pack, controller, throttle grip), for an existing mountain bike. Try for a 48VDC system, as it has greater torque, for hills and such, than 24VDC (or 36VDC) systems. And a 500 watt motor would provide enough power to go just about anywhere, although a 250 watt motor would work just fine, if you live in a community with no hills. I suggested a mountain bike, as I did just such a conversion, about 15 years ago, by mounting a 2hp "chicken power" 2-cycle motor inside the bike frame, above the pedals. I replaced the pedals with foot pegs, removed the chain and free wheel gears (from the 26" rear wheel) and attached a half-gallon fuel tank along the upper, horizontal frame tube. The front fork had motorcycle-like shock absorbers, and a large, round 12VDC malibu halogen headlight completed the rig. The bike had a top speed of 24mph, and was street legal, in California, as long as the rider had a valid California drivers license. And the bike was a totally cool experience to ride: I sometimes passed oncoming Harley cyclists, only to have them do a quick u-turn and catch up with me at the next stoplight, thinking that I was riding a vintage turn-of-the-century "Merkel", or "Cyclone". But, to make a long story short, it's essential that all electric vehicles be designed, primarily, to be FUN. Otherwise, the performance will be just too far behind that of gas powered vehicles, for most people to tolerate their performance shortcomings. And 26" diameter wheels (fitted with street tires @ 100psi) are, according to the simple laws of physics, the most efficient size wheels to achieve maximum speed, range, and comfort from your electric bike. Anyone, who carefully thinks it through, will not purchase any of the foolishly designed (yet expensive) electric scooters with smaller diameter wheels. An electric bike, with 26" diameter wheels, will achieve about 50% more speed and range, than an electric scooter with 13.5" wheels, even though both have the same battery packs. I really don't know how the electric scooter manufacturers think that they can get away with this incredibly serious flaw. But, in China, the typical electric scooter consumer is wise to this, and will only purchase a vehicle with a minimum of 24" diameter wheels (although 26" diameter wheels would be better). In fact, if I produce a second version of my electric car, it will have 24" diameter die-cast aluminum wheels, while keeping the center of gravity the same as the original version.
all right! thanks for the advices and also for the nice story about your 2strokes bicycle conversion. i did the same long time ago, but mine was atachded to the rear weel through a friction rubber caster! that allow to keep the bicycle pedal wich, in spain, where a live, determines the legal diference inbetween a bicycle and a motorcycle, at least in those times before the european regulations. my question about teh size of the batteries is related with the position of the batts in the frame. i was thinking in have a big 12v 45 amps from a car right at the bottom of the frame to keep the gravity center al low as possible and 3 more, small ones, designed for motorcycles, on top, in order to reach the 48vots requiered. what do yo think? thanks again, sash
shastalore (author)  lobo0x76 years ago
The reason I mentioned a mountain bike, with shock absorbers in the front fork, is that in a motorcycle (or bicycle) 70% of the braking power is in the front wheel, and 30% of the braking power is in the rear wheel, if one does a controlled stop. But, in sudden stops, that ratio easily changes to 100% of the braking power in the front wheel, and almost no braking power is in the rear wheel, unless the bike has shock absorbers in the front fork (which will help keep, somewhat, a 70/30 ratio). This is critical if you use street tires, @ 100psi, for best rolling efficiency, but need to safely stop a bike that has a heavy battery pack. Also, a mountain bike frame is sturdy enough to mount a sizeable battery pack, and carry it across varying road conditions. And, as I mentioned, you should not hesitate to romanticize when designing your electric vehicle. Every effort should be made to build it, primarily, to be FUN, and zany. Otherwise, your electric vehicle will be perceived as lagging too far behind, when compared to gas powered vehicles, for most people to tolerate its performance shortcomings -including you. In fact, I see this strategy as the only thing that will prevent the demise of contemporary electric vehicles. As for mixing different sized batteries, to fit in your frame, it not only won't work, but would be dangerous. The reason I suggested a complete bike electric conversion kit is that it usually comes with several battery pack options to pick from. And you can always design your own custom battery pack, when you eventually know your rig inside and out, and feel comfortable and proficient in designing your own battery pack. 12VDC SLA/AGM batteries come in all sizes and shapes, and it would be possible to mix and match different shapes of identical Amp Hour capacity, but you would no longer have a matched battery pack. Also, electric bikes, motorcycles, and light electric vehicles all require what is called a "traction battery pack". That is, a tough battery pack that quickly discharge large amounts of current, rapidly, without burning out. And the closest battery on the market is the High-Rate 12VDC SLA/AGM battery, even though it was not designed for an electric vehicle (it was designed for emergency computer power systems). And, even then, I strongly advocate breaking open these new batteries and adding standard battery electrolyte to the cells, which complicates things, as bicycles tend to sometimes fall over on their sides (and leak battery acid!). But High-Rate 12VDC SLA/AGM's are the best available for the task, and they are, at this point, relatively few sizes and shapes available of this type.
hi, S! you are totally right in your philosophie about to keep the vehicle as fun to ride as possible. "it's essential that all electric vehicles be designed, primarily, to be FUN. Otherwise, the performance will be just too far behind that of gas powered vehicles, for most people to tolerate their performance shortcomings." yeap, and mine will be really fun fun to ride and fun to wacht, i hope. i am thinking on it as a weird mixture out 2 bikes: a good one, the front one, carrying the front suspension fork, the hydraulic brake disk, and a nice set of everything , and a second one, the scavenged one, wich will hold the motorhub rear wheel, room for the electric setup, and all the space that i think i will need, for stuff or for extra batteries due is the only way that i can extend the range, right? the idea is to make a tandem where the pasenger place is taken by an electric fellas, and allowing the room for cargo or eventually for a human passenger. it got to be strong as a rock but i can make it with a proper treatment of the lower conections inbetween the 2 bikes. i shaw a couple of designs like this in instructables, an a lot of similar conversions for 1 weeled cargo trailers, resulting in a 3 in-line vehicle. an easy adaptation to an electric pusher can by taken from this point, but i want the real thing! a very long bycicle, stable and fast as posible. light enough for still being able to move it by pedals. but capable of extend my range to at least 100 kms, being lazy with the pedals, wich means colaborate only when climbing and at the starts. i have been making some googling in sla batts and it seems to be ok for me except for one thing: heat i read that heat will kill them pretty fast, and in the center of spain we get 40C in the summer without any effort. this vehicle should withstand stayin under the sun in such conditions, wich means a few more degrees than that, due to the facts than meteo readings are taken from a thermometer protected with a shadow from de direct sunlight. this is a lot of heatand i think that this can be an issue. this is a lot of heat, wich batts do you think can be the best for very hot climas? one more question: i am a bit afraid of the treatment that you recomend specially for the leaking factor, smalls drops o streams of acid is the las thingh that i want to see in my bike, but i am still thinking in give it a try. the pictures of the batteries that i shaw did not show any clue on how to open them, they look like plastic bricks with 2 terminals emerging. so i will prefer to try first the nice way and then, if i feel like i need more of the little boxes, broke open them and flood the cells with electrolitic fluid, as you recomend. theres is any problem with this? or the treatment must to be done in a set of fresh batts? thanks!! L
shastalore (author)  lobo0x76 years ago
I already have another light electric vehicle in the works. I've accumulated a 750 watt electric motor, an electronic controller with motorcycle twist-throttle, and 3 used 12VDC batteries (from my existing light electric vehicle), for a 36VDC system. The pedals were replaced, long ago, with foot pegs. Conservatively, I expect it to have a range of about 24 miles (39 kilometers).

When designing a light electric vehicle, I urge one to plan a battery pack that will transport the vehicle, passenger, and payload, at full cruising speed, for only one hour. Too many light electric vehicles are designed with greater range (= longer cruising times), but then a larger, heavier battery pack is needed, as well as a sturdier (and heavier) vehicle, to carry the additional load. And this escalation for greater range and performance invariably creates an electric vehicle that is so heavy that it has the daunting obstacle of simply transporting itself, much less a passenger and payload. Also, are you really willing to drive more than an hour a day, doing errands?

Everything (listed above) will mount on my old converted mountain bike (with the 2hp chicken-power 2-cycle motor removed). I'll also add a fake tear-drop "fuel tank" that will actually open up as a glove box.

I'll also build a lightweight, removable side car, for hauling, or to carry an occasional passenger.

But, an important note: The mountain bike wheels will have to be replaced with a pair of diecast aluminum wheels. The side car will also require the same. The reason is that spoked bicycle wheels are designed to handle tremendous stress, but only if they lean into the turns (which is what ALWAYS happens on a bike). In short, if you build a rig of more than two wheels, with standard spoked bicycle wheels, all the wheels will warp and destroy themselves, within in a couple of weeks. They were just not designed to handle any side stresses what-so-ever. There are some spoked wheels on the market that are specially designed to handle the side stresses of a 3-wheel, and 4-wheel light electric vehicle, but proper spoke adjustment/maintenance could be a problem.

But the 3 wheeled rig you described above, with all the wheels in-line, could be built with standard spoked bicycle wheels, but the finished rig might be unwieldy, in actual practice.

Of course, I have yet to locate a set of 3 diecast aluminum (or magnesium, or plastic) wheels, 26 inches diameter. And this project has been on the drawing board for almost two years. But don't rush me, will ya.

As for your battery pack heating up in the hot climate, you could always protect it with a reflective, insulated cover (fashioned from a chromed-plastic-bubble windshield shade). But I just feel that the intense ambient heat, even in the tropics, would only enhance the performance of your electric vehicle. But you could reference the technical notes of your battery(s) and simply find out what temperature range they were designed to operate in.
KevinM6 years ago
I'm flabbergasted at your treatment of the batteries here. (wow!) Would you recommend doing this to a standard car battery? I'm wondering about mine, my van has a tendency to kill the battery somehow, and after a while it won't hold a charge from the alternator anymore. (I still have to check the voltage accross the bettery with the vehicle running) I'm thinking 'topping off the fluid' could be a solution to my problem. I'm building a desulfator for this as well, as I think it could be a factor, but still.
shastalore (author)  KevinM6 years ago
Your question is a little out of the realm of this Instructable, but I'm answering it because I have serious safety concerns: A standard automotive flooded battery is quite different from the high-rate sealed lead acid, absorbed glass mat batteries, used in my vehicle. As for your battery, the only fluid the end-user would ever add to the battery would be an occasional topping off with distilled water. NEVER top off with pure sulfuric acid. And don't top off with standard battery electrolyte solution (even though that's what is already in there). Your alternator, if properly functioning, should register 13.5 VDC to 14.0 VDC across the battery terminals, while the motor is running. If that's what you're getting, the the alternator is fine. And when fully charged, and the motor off, a good automotive battery should register at about 12.5VDC across the terminals. But that, in itself, doesn't necessarily mean that the battery has the raw cranking amps that you need. Is the battery old? Then it might benefit from a 12VDC electronic desulfator. They can be purchased for about $ 30.00, on ebay. They use very little battery power and most can be left on the vehicle, even when it's running. Don't waste your time with chemical desulfator additives on the market. Do you use the vehicle for numerous stop-and-go errands? Or do you have numerous, or high-drain 12VDC appliances on the vehicle? That could explain the short battery life. Again, an electronic desulfator may help. Also, there may be a short, somewhere on the vehicle, on wiring that is not fused. If so, turning on the key switch (short of starting the motor) may cause the battery to quietly boil inside, indicating just that. Also, check with a good mechanic, about the brand names of good, reliable batteries on the market. It your battery woes are from heavy use and demands on the battery, they will be able to recommend special high capacity brands, of the same size and dimensions. They'll also be quick to point out that that some of the cheaper brands are just false economy. There are other unorthodox ways to rejuvenate automotive batteries, but they're messy, dangerous, environmentally unsound, time-consuming, and I'm not going to go into them here. I hope this helps. Good luck.