Run to 36 volts in series with a switch to parallel 72 volts?

[Varney]

Hi I'm new to the ebike thing I just got my kit delivered and I'm on eBay looking for batteries. I want to run to 36 volts in series with a switch to parallel so I can switch between distance and power can I do that?

 

[2ndhand]

Let get this straight, you want to run two 36V batteries for example 20Amp , then switch when you need power to 72V? In theory yes you could but to be honest I would say no this is not possible. Your 3V controller would probably get fried.

 

[jasonwymer]

i know this is a pretty old thread but i feel like i have to comment. it is very possible to run two 36 volt batteries in parallel while being able to switch to series. I have seen many threads talking about theoretical switches for doing this but the easiest way i know of is to have two separate wire harnesses on that provides a jumper between the batteries and connect to the controller of 72v and on that just connects the wires in parallel for 36v and charging.

 

[Elevatordude]

Hi I'm new to the ebike thing I just got my kit delivered and I'm on eBay looking for batteries. I want to run to 36 volts in series with a switch to parallel so I can switch between distance and power can I do that?

Anything is "possible" but running 72V through a motor that is designed for 36V can, and probably will, eventually damage the motor........but you will get more rpm out of the motor and it will run much faster if speed is what you are looking for. The other problem with more speed is that the stress moments generated on the rest of the bike increase disproportionately. I've seen frame welds break and spokes blow up. Both potentially catastrophic events if one is traveling fast. I have found that I don't bounce as well as I used to so I don't push my ride that hard anymore.