Kawasaki KZ440 Electric Conversion

[Ben Nelson] didn’t even know how to ride a motorcycle when he started on this electric conversion of a 1981 Kawasaki KZ440. The engine wasn’t a loss since the bike was nonrunning when he purchased it for $100. The permanent magnet Etek motor was $500 and each of the four yellow top batteries were $160 (only three pictured). He says that the majority of the conversion work only took two weekends. The resulting, still street legal, ride averages 20 miles per charge with a 45mph top speed.

More electric motorcycles on Hack a Day:

[via Ecomodder]

11 thoughts on “Kawasaki KZ440 Electric Conversion

  1. again… the problem is, unless someone wants to invest the money in real batteries, and stop using this 12v Yellow Top Optima deep cycle batteries, you’ll never get past this 20-30 mile range and 40mph crap. That wouldn’t help me at all for even just my commute to work.

    Good concept, great that people are doing it, it just needs to be taken up a notch is all.

  2. Unless I missed something the article gave the range as 20miles flat, not 20-30, but still, that would be plenty for most of the driving I do, as long as the batteries can be recharged in less than an hour. Considering the quality of parts this guy used (no ESC, SLA batteries), I’m surprised the conversion cost 2k. Assuming this could be done for less than 1k, it would definetly be economical, as long as you work less than 20 miles from your home, and live somewhere with a nice climate.

    The only thing I wonder about with these electric mods is the lack of a gear shift on most small systems, it be interesting to see some torque/rpm or efficiency/rpm graphs.

  3. well, he didn’t spend much on the frame, only paid for batteries/controller/motor and some other support parts. 1500 for a conversion is pretty good… less moving parts, less maintenance…. plus 1kwh to charge it, at less than 10cents, thats less than 1 cent a mile. Who cares that it can’t get 100miles… lots of people ride motorcycles and scooters because they’re good for commuting and save gas. Thats the whole point. He could drive to and from work for a month on what it would cost for one gallon of gas. Ben has been doing a great job, I’ve been following this for a while. Its amazing what someone in his garage can do….and he’ll laugh every time he passes people pumping gas at the gas station.


    The power band for an electric motor is not at all like an ICE. Its got max torque at 0rpm, instant acceleration. Power is fairly flat until you start aproaching the RPM limit of the motor, and then the torque falls off. You don’t need a gearshift for 0-5000rpm for most EV motors… and depending on gearing, this can get you up to speed pretty fast, and have a pretty reasonable top speed. And he did use an controller, thats what the alltrax is.

    until Lithium comes down in price, you’ll keep seeing Lead Acid. NiMH is hard to get, lifepo is expensive, Nicad is useless, Li-Cobalt explodes (laptops)… so there’s not a ton of options. Lead has more current delivery capability than any other chemistry, cheaper, easier to get.. and is a good option for most people. When lithium falls below 2 grand for a pack for my motorcycle, I’ll consider switching from SLA, but until then, its not a good choice economically.

  4. @6: Agreed about the gearing. I’ve been in electric cars that did 0-80 with reasonable acceleration with just a fixed reduction gear. The Tesla roadster uses a two-speed transmission, mostly because of its high top speed. I understand they’re having some trouble with it lunching its transmission due to all the torque.

  5. actually, they ditched the two speed, and went with a single speed, liquid cooled their motor and controller to increase performance so that it would reach the speeds and performance numbers they originally quoted. They don’t NEED the two speed… just one. The first generations will be 2 speeds, but will be retrofitted when the single speed gearbox is finalized. It sure lightens things up too.

  6. i like it!!! much bigger scale then a curent project of mine (i’m useing the gastank to hide the batteries and charger tho) sofar on test runs i have gotten 30mph and about a 70 mile range useing 36v (3x12v)scooter batteries on a hopped up bananabike that zapped me everytime i accelorated on its first run

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