The best way for LiFePO4 battery charging is CC/CV mode, that means constant current then constant voltage for a charging way.
Exactly to say, here are three steps for A typical charging way of LiFePO4 battery, When battery is almost empty, we need to offer a very small constant current to "recover" the battery voltage into nominal state. After this step, big constant charging current can be accepted by LiFePO4 battery. Always here is a mark on charger, as "XX V, XX A", that means the volume of constant charging current is the "XX A". The constant current state is the most important state for battery charging, which makes battery been charged from 5% SOC to 90% SOC. After constant current charging step, the final step is the constant voltage step, Make sure that charging voltage have been fixed as up to 3.65V, then small current would be given to feed the batteries till they all fully charged. In this state, the balancing function would be finished, so cells in battery pack would have almost same SOC state. When battery pack is discharging, all cells can act as the same way, battery pack would got stable performance.