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I'm sure everyone has seen the Chinese bms that is on aliexpress. 24v ,200 amp.
The wire feeding it look like a pair of numer 6 copper.
I don't get it . There's no magic involved , so what is the true capacity? Or is it just a bunch of smoke and mirrors?
Greg
 

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200A is probably peak for a few seconds, assuming MOSFETs there are actually correct kind - many of these products come with random parts. I.e. if you order two of the same, you may find parts being different, with different specs.
 

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I've tested this '80A' bms on a 150Ah li-ion pack.

80A continuous was no problem, even tried 200A for half a minute...didn't die

So yes they can work, but not for a car, more like moped etc.

balancing current is usually low (like 30mA), and balancing voltage (fixed) too high (4,18V, 4,2V) disconnect voltage usually 4,25V / cell
 

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sorry I don't get it...please explain :)



here's some pictures of the one I have.
 

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Never mind, I found more pics, it's 10AWG. Most sources put 10AWG with 200C insulation at 90A max.
I'd use it for 80A max, not continuous...

But...I was surprised I didn't break it while testing at 80A continuous, and even 200A for 30 second.

I'ts place is in small batteries, mopeds, outboard motors, etc.
 

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Well, it's a product of MOSFET specs and the cooling. If those MOSFETs are overspec'ed for 80A, then they may hold more. The thing is, the one you pictured in your testing is likely different from the one on AliExpress website. I.e. made by a different actual vendor. It is often the case that even Chinese products are copied by other Chinese companies without necessarily adhering to original design specs.
 

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Well, it's a product of MOSFET specs and the cooling. If those MOSFETs are overspec'ed for 80A, then they may hold more. The thing is, the one you pictured in your testing is likely different from the one on AliExpress website. I.e. made by a different actual vendor. It is often the case that even Chinese products are copied by other Chinese companies without necessarily adhering to original design specs.
I always use 'greenstore' also for Elcon chargers.

https://greenstore.aliexpress.com/store/708582
 
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