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What is the best way to power this motor? Answered

I'm tempted to build an electric bike. I will be using a 4000W Hubzilla hub electric motor. I need about 100V and 80A at max.

Batteries are really expensive, so what kind of battery(s) can I buy for under $600 that would match this motor and give me roughly 20 miles? I'm not incredibly worried about weight, but under 30-40 lbs would be superlative.



1. The motor isn't 4 Kwatts continuously rated . I don't care what their web site says 100 volts x 80 amps is 8000 watts just by the way.

For many reasons - e.g your not going to pass 40 amps down those wires for long., the windings are far too small a gauge for that power etc.

A 250 watt continuous rated motor weighs in at about 20 lbs and is a fair chunk of machinery - see picture -

2. Pulling 8Kw from a battery pack under 40 lbs - it isn't going to last long.

3. Assuming this motor consumes 250 watts cont - Assuming your vehicle weighs under 150 lbs then with reasonable gearing you could get 30 MPH and a range of perhaps 50 miles.

See my electric car instructable.


it's real - I built it and know how it performed.


I later realized I don't really need to worry about amperage, just voltage and amp-hours. :P

I wouldn't be running it at 4000w for any length of time either. :P

Thank you though. Your comment was helpful, and I am finding some nice battery packs on alibaba and other sites that will do.

Thanks again.


5 years ago

Always happy to help a marzipan lover.

The Tesla electric car company is using a liquid cooled floor full
of Lap-Top Lion batteries but they are watching each cell with a uP.

Your other options are Lead-Acid gates like six-pack and NiCad.