BMS on eBay

Batteries, Chargers, and Battery Management Systems.
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Peter Brigg   10 W

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BMS on eBay

Post by Peter Brigg » May 14 2018 6:55pm

I have had problems with BMS on my 12s LiFePo4 electric bike pack and I am looking at buying a bms with this eBay number ( 321048908605 )

The pack is driving a 350w motor so my arithmetic tells me watts divided by voltage equals amps so approximately 10amps is the theoretical figure for the BMS. Plainly I need to go a lot higher than that-perhaps a 36v 60amp BMS.

Something I am not sure of is the quality of these generic BMS-if they fail they can ruin expensive cells-are there quality reliable BMS available?
Thanks

Peter

markz   100 GW

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Re: BMS on eBay

Post by markz » May 14 2018 7:26pm


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amberwolf   100 GW

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Re: BMS on eBay

Post by amberwolf » May 15 2018 1:46am

Peter Brigg wrote:
May 14 2018 6:55pm


The pack is driving a 350w motor so my arithmetic tells me watts divided by voltage equals amps so approximately 10amps is the theoretical figure for the BMS. Plainly I need to go a lot higher than that-perhaps a 36v 60amp BMS.
Can your cells (and the internal and external battery wiring) handle 60A? If not, you sure dont want a BMS that can output that much.

You want a BMS that will limit current to at most whatever the max the cells and wiring can handle. ANy more than that and the cells and/or wiring can be damaged by pulling more current from them than they are designed for (if the motor/controller happens to be able to do so).

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