View Full Version : EV Bike power efficiency?

01 December 2010, 0520
Hey guys. I've been tooling around with the EV spreadsheet, and according to it with the weight of 60ah batteries, at 80km/h, the bike will use 50wh/km - giving a range of 71.8km! Nearly 72km out of 3590.40wh (48ah usable at 72v nominal)!!!

This seems a little bit optimistic to me. I'd be very happy if it was possible, though, as 60ah cells will save me quite a bit of money over 100ah cells, and are more likely to fit in my bike.

So my question is: What kind of wh/km or wh/mi are you guys with actual working bikes getting?

01 December 2010, 0800
Actually sounds pretty reasonable compared to what others have achieved.
Just remember that their are two parts of the battery equation. The total usable capacity will determine your range, but the peak rate you use it will determine your cycle life. Pick batteries and C rates that match your intended usage. As an example, a battery such as a TS 60Ah LiFePO4 will happily deliver less than 1C continuously and up to 3C for short durations and still give it's rated cycle life. But if you ask it to deliver more continuously or ask it to deliver > 3C on a regular basis, the life of the battery will be affected.

01 December 2010, 0828
My GPR-S, when it is running, uses around 1 Ah per mile at a steady speed of 40 mph and 2 Ah per mile at 55-60 mph (full throttle). So I think your estimated range is correct, provided you travel on level ground and keep the speed under 80 Kph. Cut that in half, along with your battery life, if you give your bike full throttle most of the time.

01 December 2010, 1216
Last month I averaged 118 Wh/mi.