Convert Sunrunner LifePO4 24v to Li-ion

[rich110]

I have a Sunrunner ebike that I got as non-working/dead battery. I hooked it up to 21.8v and it operates the motor at low speed on the throttle, at 25.4v it went a little faster. This is with no load (wheel in the air) and running from nimh AAs just to test if it's worth spending more money on as I don't have an existing battery to test with.

The original battery is 32 cell 24v 6Ah lifepo4 which I assume is 8s4p, cells rated at around 1.5-2.25A/cell current (details are hard to find).

24v 10Ah lifepo4 is £300 any smaller don't provide enough current, 24v 10ah liion is £125

Can I buy a 24v 10ah li-ion standard battery and just drop in?

lifepo4 8s would operate 20.0v - 27.2v voltage range
liion 7s would be 21v - 29.4v

Is there a chance that would blow the controller? Does the controller run at reduced speed because it senses the battery voltage, which might give me issues because of the different voltage profiles of the cells?

 

[Nealh]

24v lion will be fine, controllers capacitor ratings are never that close to the battery voltage and if you were to peak in the controller one suspects you will find 50v caps in there.

 

[guerney]

It's a wild looking bike

Sunrunner 24v bike repair

I'm trying to help out a local ebiker wth this , it transpires, unusual bike. It is 24v system , the battery is a mere 5ah in a handlebar mounted box. Crucially it is Lifepo4 The controller is mounted in a box by the front fork it has an integrated led light. The motor has some markings and I...

www.pedelecs.co.uk

 

[Nealh]

My swizzbee was nimh 24v so I changed over to 24v lion my controller would happily have accepted 8s lion.