Newbie to here with all wheel drive

[coolreptile]

Hi everyone I'm John from Lincoln and got into electric bikes a couple of months ago and got the bug lol. I commute to work daily at 4am all the way on a nice empty cycle track and then across a field I have 60v at 18ah on my back wheel and 48v at 20ah on my front wheel with a nice big 48v light for an off road car so I can see really well. Acceleration is amazing with all wheel drive but yet again I've bought another 60v 15ah battery as im sad and obsessed or just mad as a hatter so my question is do I just add it to my rear 60v battery for more ampage or swap it to my front for that little bit of extra speed as I'm slightly concerned of adding different ampages together as I think it could slowly destroy the lower ampage battery but unsure on that so any help would be appreciated

 

[Fat Rat]

Hi
Welcome to the site

 

[Benjahmin]

You can run batteries in parallel, so long as they are the same voltage. Start mixing voltages and you'll be in for a call to the fire brigade.
You could run batteries in series (so increasing the overall voltage) but:
1 your controller must be able to handle that voltage.
2 each battery must be capable of handling the maximum current draw.
3 will your motor handle the extra voltage and/or current?
Also, I'd be a bit circumspect if I were you. It's moot whether 48v batteries are legal or not, let alone 60v. It depends on the interpretation of the regulation wording. I believe it states a maximum of 48v, of course they charge to 52v so......?

 

[coolreptile]

Cheers benjahmin I wouldn't dream of mixing voltages as that would be really dangerous to say the least I don't actually go on the road at all in my 5 Mile trek to work so legality isn't a problem I doubt my motor would handle 108v so not even going to try as that could be very expensive lol. My front controller can also handle 60v as tried my rear battery on it and it didn't go bang but would be very unsure adding any more voltage than the 60v battery. My main concern was damaging my 60v 18ah battery adding a 60v 15ah as I thought the 18ah would suck the life of the lower ampage one and damage it . Still unsure what to do though wether to go 60v both wheels or add the ampage to my rear wheel as I admit my bike is plenty fast enough but a mile or two faster would always be fun lol

 

[signwave]

I don't actually go on the road at all in my 5 Mile trek to work so legality isn't a problem

What about the 'nice empty cycle track' you mention?

The 'law' applies to all land that the public has access to, not just roads.

 

[wheeliepete]

Are you running identical motors front and rear? if so you would be better running them both at 60v, as they will spin at the same speed, otherwise the faster motor is dragging the slower, which defeats the object of having two motors. Do you have both motors running off one throttle?

 

[coolreptile]

Yes identical motors and two independent throttles, batteries and controllers. The 48v front motor aids the rear motor to get up to speed very quickly and helps keep it at speed although doesn't contribute to the actual speed of course as the final few miles an hour are achieved by the rear motor although the speed is much less just running the rear on its own

 

[wheeliepete]

Cool, would be interesting to see any difference running both at same voltage. Can I ask what motors and controllers you are running.

 

[coolreptile]

Both motors and controllers from volmart so no high rewinds etc etc as I quickly realised that both motors would take a lot more voltage and only heat would really kill them and they both run fairly cool as do the original 48v (Chinese) controllers. I thought apart from getting up to speed faster the all wheel drive wouldn't actually gain me any speed but in reality it does so yes it will be interesting to see if moving the 48v front wheel up to 60v would give me a few more miles an hour as well as in theory it shouldn't as they should both top out at the same speed but theory and practice aren't always the same thing.