Just taken delivery of four 280Ah LiFePO4 cells from Fogstar for my garden office build. Cracked open the box and the cells are reading anywhere between 3.27V and 3.41V — that's a 140mV spread straight out of the packaging. Not ideal when you're trying to do a proper top balance before building the pack.
I've got a decent bench power supply (a Korad KA3005P) so I can top balance them individually at 3.65V, but it's going to take ages given how far apart they are. Is there a sensible order to do this — charge the lower ones first to get them closer together, then balance in parallel? Or just bung them all in parallel at 3.65V and let them sort themselves out naturally? The Daly 100A BMS I'm using won't arrive until Thursday so I can't rush this.
Genuinely surprised the cells weren't closer matched from the factory. Are Fogstar just shipping them straight from CATL storage with no pre-conditioning, or is this par for the course with budget prismatic cells these days?