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Is a BMS for lithium battery charging only critical when charging the cells in series?

If one were to come up with a clever switching "mechanism" to charge the cells in parallel, and use them in series, would that negate the need for a multi-segment BMS?

thanks,
jp
 

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So what? a 3.2v charger system?

Don't you get the battery balancing problems whether you do it in series or parallel?
Somebody will no doubt correct me if'n I'm wrong, but I think the problem is that with big juice across a series combo of batteries, the real problem is that the individual characteristics of the different cells determines how much voltage appears across each one. Basically, ohms law. With a certain amount of current flowing through the whole lot of 'em, the voltage across any individual cell is going to be proportional to it's resistance.

The worst battery in the group winds up getting too many volts across it, and thus the potential for explosion and fire.

If they are all in parallel, the charger controls the voltage across the whole lot of 'em. If one of the batteries had an internal short, it could still cause a big problem, but I think that is not the typical failure mode for these batteries. Also, the switching mechanism of which I speak so vaguely, could just as easily have an individual current limiting resistor or even a fuse in series with each cell during charging.

jp
 
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