I’ve a 12s6p battery, with integrated BMS. (I say integrated, as it’s all wrapped up together.) And a YZPOWER-450 power charger…50.4V 6A. I’ve also got two meters on this thing - you can kinda see in the pic: a circular volt meter and a rectangular percentage meter.
Here’s my question: how long past 100% should the battery remain plugged into the charger? When my level meter read 100%, my volts read at 50.6. When the charger LED indicated that charging was complete, it was one hour later and my volt meter read 51.2.
Relatedly, am I correct in only disconnecting the line to the controller, when charging? …Or is that even necessary?
Maybe your cells are balancing After your 2 hour wait all cells should sit at 4.2 volts max with no missmatched readings among inner battery groups.
DISCLAIMER some BMS’s chargers have different voltage tolerances often a little lower than max max. This is OK just make sure it’s not overcharging anything.
Overcharging your battery is never healthy, it’s even dangerous. Can you meassure voltage directly at battery terminals with multimeter? Those cheap voltage meters often show a little but wrong values
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yeah, But if that’s not then is the charger/power-supply off? (would seem unlikely)
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Check with multimeter first.
It is possible that your charger is off a little bit. I had batch of 5 chargers, all of them overcharging.
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Yeah, those are what I’d consider cheap voltage meters.
The rectangular one can change between volts and percentage. At one point, I had it set to display volts, and in parallel with the circular meter…and they were reading different. Granted a minor difference, but still.
So checking with multimeter first, means measuring voltage directly at battery terminals? I can handle that, I just want to make sure before I open it all up.
That would be terribly disappointing to go through 5 chargers.
Yes, battery main positive and negative 
you will get real voltage reading there
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