The lithium iron phosphate (LiFePO4) battery voltage chart represents the state of charge (usually in percentage) of 1 cell based on different voltages, like 12V, 24V, and 48V. Here is a LiFePO4 Lithium battery state of charge chart based on voltage for 12V, 24V, and 48V LiFePO4 batteries.
Lithium ion batteries are becoming increasingly popular and require a different equalization voltage than lead acid or nickel-cadmium batteries. Battery equalization voltages for lithium ion battery packs should be between 1.8 and 3 volts per cell in order to maintain performance.
Working principle That equalization system is able to adjust each cell to be equal can avoid the phenomenon which in-pack cell overcharge or over-discharge occurring. For lithium iron phosphate battery series, data acquisition module collects the real-time data of in-pack cells involved terminal voltage, working current and temperature.
Lithium iron phosphate battery voltage change dramatically in the end of the charge and discharge, it means that voltage difference is obvious between in- pack cells even if the battery SOC were similar, the voltage-based equalization algorithm is more advantageous to improve the inconsistency of the battery pack at this stage.
Here is a LiFePO4 Lithium battery state of charge chart based on voltage for 12V, 24V, and 48V LiFePO4 batteries. Individual LiFePO4 cells typically have a 3.2V nominal voltage. The cells are fully charged at 3.65V, and at 2.5V, they become fully discharged. Here's a 3.2V battery voltage chart:
A battery-equalization scheme is proposed to improve the inconsistency of series-connected lithium iron phosphate batteries. Considering battery characteristics, the segmented hybrid control strategy based on cell voltage and state of charge (SOC) is proposed in this paper.