Hi, I have an electric scooter that runs on a 60v lithium battery. I would like to hook up a backup battery while keeping it isolated from the main battery because they don't have same specs. I thought I could use a power switching circuit breaker of some kind. Any Idea on how I should wire it up? Should both batteries' negative ends be connected together with their respective positive ends going through the switching circuit breaker?

 

The simplest would be a high-current SPDT toggle-switch.

Do you know how much current the scooter motor takes, or its power rating?

Yes, you can connect the two battery negatives together, and switch their positive sides.

 

The simplest would be a high-current SPDT toggle-switch.

Do you know how much current the scooter motor takes, or its power rating?

Yes, you can connect the two battery negatives together, and switch their positive sides.

Thanks for your answer. My scooter is rated at 2000w. There's a 63A DC circuit breaker already in there. I was planning on swapping it out with a 63A switching circuit breaker like this one:

 

The only question I have is, why would you want to carry a heavy lead battery as the backup?

 

It's the battery that came bundled with the scooter. I'm planning on swapping it out with a lithium battery at some point but, till then...

 

Are the lithium and lead batteries the same voltage?

 

My scooter is rated at 2000w. There's a 63A DC circuit breaker already in there. I was planning on swapping it out with a 63A switching circuit breaker like this one:

That's okay as long as you never turn both breakers on at the same time.

But 2000W is about 33A @ 60V, so you could also use a 30-50A SPDT toggle switch to connect one of the two batteries before the breaker you have.

 

That's okay as long as you never turn both breakers on at the same time.

But 2000W is about 33A @ 60V, so you could also use a 30-50A SPDT toggle switch to connect one of the two batteries before the breaker you have.

With these breakers you can't turn both of them on at the same time. If I Turn one side on, the other will turn off automatically. I already ordered it so I think I'll just put it in place of the existing one.
Thanks, you've been very helpful.