Hey Guys

This is my first post on this forum. I have been looking over the conversion topic and it seems to me that the most important factors are battery weight and battery longevity. A lot of people that are using lead acid batteries state that the batteries last about 3 years before they are shot. A lot of these same batteries are used in the home power (solar/wind) markets with much greater longevity (6+years). I have also read that the rapid discharge (stomping on the throttle) eats up the charge on the battery and MAY also damage the battery. I used to drive semi in cold weather. We discovered that you could get these battery sized capacitor packs (about $600) that made it much easier to start the trucks and the batteries seemed to last longer.

My idea would be to get enough of these capacitor packs to counter the voltage sag generated during acceleration (say 15 seconds worth). The numbers for the hand tools market are promising. A battery operated cutter(high amp draw) went from being able to make a few cuts to being able to make over a dozen. If this would allow the battery pack in a EV to even double its range, it would be worth considering on that alone(running one string instead of two). However if it would also extend the life of the battery it become even more interesting.

Something along these lines:

Anybody know about or ran across any links on this topic?


ZAP states that they intend to use caps on their ZAP-X for accelleration. I briefly mentioned the idea to a self-proclaimed electronics expert (not myself) and he said that caps are only good for quick and instantaneous bursts of energy. He said that anything big enough to make a significant difference in accelleration would be like dumping the clutch at 5000 rpm at the dragstrip thus trading one problem for another.

I have no idea how or even IF one could control the speed at which the energy is released from a cap. I think that would be the deciding factor. If it is possible to get a slower “burn” from the cap that would do a lot.

Great question / idea. I’ll add it to my list of research subjects, but don’t hold you breath for my findings. :wink:


i was actually going to incorporate this idea in the bike i was designing… i was going to solve this problem by having the charge from one BIG capacitor to a few smaller ones, and have it set on a gradual time release so that every 1/4 second (depending on setup and size) it would release the charge from the smaller capacitors, and when they weren’t in use for acceleration such as as consistant draw, the big one would be refilled by the battery so that the battery would have a consistant draw on it giving it extended range/life (almost like a gas motor doing the same thing but with fumes instead of gas)

the problem though was that capacitors dont hold very large charges and still add lots of weight (nothing compared to a battery but still…)

This is worth a read, from someone who has used capacitors in an EV:

[QUOTE=Lazlow;248]This is worth a read, from someone who has used capacitors in an EV:[/QUOTE]

thats an awesome link, i like his setup, but i need to do some more research about controllers before i start building anything.

Check this out: