Another battery question

RegularGuy

Pedelecer
Jan 9, 2012
34
0
Farnborough, Hants
Apologies if been answered before, did search for it but couldn't find answer.

So I'm a gnats breath from ordering everything for my conversion project. I commute 25 miles, most of which is along a fairly flat canal (as canals are). I do this at present unpowered, but it's a bit much everyday. Would like an electric bike to help, but dont' want to ride it like a motor bike, I'm doing it for the exercise as much as anything else.

I can also charge at work no drama, so it's only really got to do 12-13 miles between charges.

I intend to to run it on a 250wat 36 volt front wheel hub.

Question: will a little 9ah bottle battery be enough? I realise that these supply less of a constant discharge than a big 15ah beast. But would the smaller, bottle battery suffice?

Will it:
A) go the distance say 13 miles between charges.
b) Will the 10a constant discharge make a huge difference compared to the 15a constant discharge of the larger 15ah battery, given I'm planning ot run it on a modest 250 watt 36volt motor rather than some big illegal thing.
 

flecc

Member
Oct 25, 2006
53,152
30,567
Yes, a 36 volt 9 Ah battery will easily cope with that 13 miles and should be plenty for the round trip of 25 miles with some to spare. That will be especially true if you are putting in a reasonable pedalling input. The discharge rate will not be a problem either, since on a fairly flat route you'll be running at a good speed near to the point of maximum efficiency (circa 12/13 mph) when the discharge rate drops.
 

RegularGuy

Pedelecer
Jan 9, 2012
34
0
Farnborough, Hants
Great stuff. I like the idea of the bottle as it's so neat. I also want to be able to use it to help pull my little one along on the tagalong which a big rear battery may interfere with. Those are much shorter runs, maybe 5-8 miles although a little hillier. Again I can peddle that far with the little one myself, but a bit of assistance say 30% or even 50% if she's feeling tired and not contributing would really help.