lithium question

Can you use an LA charger for LFP? Yes... Should you? No, at least not without reservations. A well regulated charger should work, but it will depend on the BMS installed in the battery to disconnect if over voltage. That is what they are designed to do, but it is not what they were designed to do in routine charging. Also almost every LFP vendor will tell you not to float charge LFP packs. If the float charge is set low enough, it does no harm. And if you have an LFP battery bank with no BMS, the you are risking damaging the cells and possibly a nice fire.