Hello

[AlanB]

Hi,
Just registered and thought I'd better say hello. I live in Northamptonshire and I've been offered 2 Powabike Cambridge bikes, both of them have faulty batteries.

If possible I would like to ask the following question:-

The bikes have 24v Ni-Mh batteries, can I open the battery cases and put 2 x 12v SLA batteries in series and buy a 24v SLA charger to recharge the batteries as required?

Thanks in anticipation for your replies

Moderators...if you would like me to start a new thread in the technical section for this please let me know.

Regards,
Alan

 

[Deleted member 4366]

That should work.

 

[AlanB]

Hi thanks for replying, should be an interesting project, is there anything I need to be aware of in doing this?
One thing I have thought of is the capacity of the SLA batteries, should I get to 8Ah ones or 10Ah ones, one of the bikes will be used by my daughter to go 3 miles to work and back, the other bike will be for me just for leisure and popping to the shops,
Thanks,
Alan

 

[Deleted member 4366]

The more the better.

 

[AlanB]

Thanks again for the reply, I picked up the bikes today, and it looks like SLA's will be too big to fit in the old ni-mh battery case, what other cheap options can you recommend? I have a budget of £50 per bike.
Many thanks
Alan

 

[flecc]

That's usually the case with SLAs Alan, they are bulky for a usable capacity. There isn't really an alternative with that budget, lithium or the NiMh being about five times that per bike. I can only suggest the SLAs mounted elsewhere or the battery case enlarged to suit.
.

 

[Alan Quay]

Stick a rack on the back, chuck the batteries in a tool bag.
Don't expect much range.

 

[AlanB]

Thanks everyone for the replies, I have ordered some of these to have a play with. http://www.batterybayuk.com/batteries-chargers/electric-bike-batteries/electric-bike-batteries-from-leoch/pack-of-2-leoch-12v-8ah-7ah-sla-batteries

There is a rack on the bike, so I will use that.
I put both of the original Ni-Mh batteries on charge last night, I have power now if I lift the back wheel, both of the bikes will turn the wheel, but as soon as I put the wheel down is just judders, I guess I can't draw enough current out of the old Ni-Mh batteries.
I will hook up the SLA's when they arrive.

I will let you know how I get on,

Kind regards,
Alan