In this case it does sound necessary because he can’t charge through bms. It’s a good thing to have either way.
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Firstly measure all your P-packs with a multimeter. As long as none are near 4.2, put the charger directly on the battery ends for 5 minutes (charging directly, bypassing the BMS), then check all 10 P-packs again. Never leave it connected unattended and just do it for short times, and keep checking voltages with the multimeter.
Bring it up high enough for your BMS to work, but don’t exceed 4.2V on any one cell.
Would either of the chargers that I posted work or no? Also, I have access through my school to a straight power source if that would work. With that line of thinking, if i set the power source to release a 7v output at 4A, would that be viable for charging each of my 2s batteries? If i followed the steps you outlined? Or would you recommend just sticking with a charger?
It’s just a handy tool to have around in case of a situation like this with Lipos and could also be handy for maintenance charging of Li-ion cells or P groups individually.
Gotta disagree. Many lipo packs have cycle life in the 50-150 cycle range. As they age you might want to check capacity, internal resistance, etc etc.
But then I’d feel the same way about li-ion packs…
That’s the point I was making
Do you think the method that I suggested would work?
The most important part is stopping VERY often and checking the voltages. You cannot exceed 4.2V or go under somewhere around 3 volts. You can cannot charge OR discharge any of them at too high a rate, which the 7V 4A one might do
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@ArsenalMain It’s much easier and safer to do this with a hobby balance charger. And the cells will be balanced when charging is complete. And it is important for the cells to be balanced before reconnecting them to the bms.