Charging a 100Ah LiFePO4 battery like the DEESPAEK 36V model typically takes 5-10 hours with a standard charger. Time varies based on charger output (20A chargers take ~5 hours vs. 10A at ~10 hours), depth… How Long Does It Take to Charge a 100Ah LiFePO4 Battery? Such as DEESPAEK 36V 100Ah LiFePO4 Battery