How can I switch from main lithium battery to backup lead battery in electric scooter?

Thread Starter

AnotherRumplestiltskin

Joined Feb 28, 2024
4
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?
 

crutschow

Joined Mar 14, 2008
34,455
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.
 

Thread Starter

AnotherRumplestiltskin

Joined Feb 28, 2024
4
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: EDrop_1709148764063.png
 

crutschow

Joined Mar 14, 2008
34,455
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.
 

Thread Starter

AnotherRumplestiltskin

Joined Feb 28, 2024
4
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.
 
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