I need a configuration that will give me 120km (100MI) range. My WE motor with Ping 36v20amp gives me 50km range average on a single charge. I therefore know that three of these will meet my requirement. However, are their more economical options ? For example will a SLA battery configuration of 3X 12v20ah batteries give me enough juice ? Does 60AH of SLA batteries compare to 60ah of lipo4 batteries ?
I would really like to hear different configuration ideas....
I will be mounting batteries on a trailer because of weight.
Huge difference in battery type... weight, and thus, range. Another tradeoff for distance is speed. The motor itself will also have an optimum pull speed that it is looking for. The more weight you carry to achieve distance, the slower the bike will go, and to extend range, you would have to ride at less than full thruttle. Eventually all these factors will "hit the wall", and there is only so much you can do. Bigger motor? More juice. Another option is build on the lightest bike you dare, with the lowest rolling resistance you can, and maintain safety. Good luck :-)
60Ah of SLA batts is quite a lot worse than 60Ah of LFP or Lipo batts. For two reasons.
1) the batts are about 3-4 times the weight, and all that weight has to be shifted, so you get less range.
2) The SLAs have a much stronger Peukert effect, which means that as discharge rates rise so does effective internal resistance, which means that more of the battery power ends up in hot batteries and less in the motor. This effect is more significant for acceleration and hill-climbing than range per se (because best range is acheived at low discharge rates), but because the lithiums have lower internal resistance at all discharge rates you will get better range from the Lithiums.
http://www.smartgauge.co.uk/peukert_depth.html (proper hard sums!)
A better way to do it is like what I did...
I have 2 motor's both 36v 350w each...
I use a 36v 25ah Front and a 36v 30ah Rear LiFePo4.
I get about 120km with those, even doing about 18 mph....
Front motor is 24" and Rear is 20"
On the Front motor If I do ~7 amps of power and on the Back Motor i do ~9 amps of power, I can steadily do 20.5 mph and so I can do 3 hours of that for a total of 60 miles
If I draw a little less and do 5 amps front and 7 amps back I'm doing 18 mph and reach a distance of approx 90 miles (Best day record for me was 18 mph wind behind me most of the day, did a total of 111 Miles at BMS LVC.)
(Mind you, I have a HEAVY Bike with Speakers (subs) and alot of other electronic equipment) Total weight with me on it approx. 320lbs (145.5kg)
I say, If you can get 2 36v 30ah LiFePo's on a 24" or 26" configurations with 2 motors, on a lighter bike frame than mine (i.e. 140lb/63.7kg) I'm POSITIVE, you can get 120km/100m out of it!
(Of course, the Cost of 2 36v 30ah LiFePo4's will cost you about $1000 USD, but hey it's worth it for 20mph for 100 miles)