I've got a setup with 32 LiFePo4 batteries, 280Ahr each, that have been sitting for a couple of years. Most of them are at a voltage of exactly 3.32v, but three of them are lagging behind at 3.28v. Do I need to do anything special before I install them into a battery management system (BMS) for this system? Is it okay to use a Li-ion charger to bring up the charge even though it goes up to 3.6v and I can't control the final voltage?
1 Answer
If your BMS has an active balancer, you can just connect them, charge them up, and let it handle the balancing. Alternatively, you could put all the cells in parallel and let them sit for a few days to equalize. Of course, if you're keen on getting all three of those lower cells up to 3.32v first, that's an option too, but it really depends on how much effort you want to put into it.
Yeah, I hear you! I prefer to be efficient too. My dad doesn’t buy that either.
That's true, but some balancers can be pretty slow. I have one that uses a 1A balancer, and it took two days of consistent charging just to balance everything out. Still easier than connecting them all in parallel and hoping for the best.