Hi, so few days ago I got 2 battery packs from a guy in my area, and he told me one or both of the packs are probably unbalanced and said I need a balance charger which I don’t have and looks expensive as hell for a 12s. From my previous knowledge of batteries and what not, I thought you could use the bms and leave it plugged in after its green to balance the pack and keep it balanced. Can I use a bms to balance these packs? or are bms only for balancing minor voltage difference like in the decimals?
yes, most bms have balance function. some even can be fine tuned to extreme delta
u should check this thread out
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Oh thanks.
He also gave me a bms but idk any info if anyone knows the model. Im thinkin about just getting 2 smart bms from LLT power.
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Looks like one of these. They’re a good bms. Not sure if they freak out when there’s a huge voltage difference or not. I like the LLT Bms where you can see if it’s balancing or not on your phone 
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Good BMS, it’s a SuPower one, like matt said. not “smart” like the bluetooth LLT but good nonetheless
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Just read the supower website and it says dont use with imbalanced batteries, but it does have a balance function. Do you have any experience with the LLT bms for balancing unbalanced batteries?
This might be stupid, but can i use the balance wires to check the voltage of each s group? The battery is in like a plastic box, i dont wanna open it up.
yes you can, you can either keep your negative probe on the negative and work your way up the balance plug with the pos, or go negative Probe to negative, pos to cell 1, then negative to 1, pos to cell 2 etc. that’ll show individual cell voltages
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unfortunately not. biggest imbalance I’ve had was 0.5V and it levelled that
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negative probe on the negative wire on the balance port or negative output?
and then - to cell 2 and + to cell 3, then - to cell 3 and + to cell 4 and work up like that?
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they are the same, but i would do it on the balance port, becareful not to short out when u probe the negative and first positive to check, they are fairly close
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bang on mate.
And as mentioned above, negative main cable and negative balance lead are the same voltage