https://footprinthero.com/lifepo4-battery-voltage-charts
Here are LiFePO4 battery voltage charts showing state of charge based on voltage for 12V, 24V and 48V batteries — as well as 3.2V LiFePO4 cells.
Note: These charts are all for a single battery at 0A. Consult the manual of your LFP battery for its specific discharge curve and voltage parameters.
Voltage Capacity 14.6V 100% (charging) 13.6V 100% (resting) 13.4V 99% 13.3V 90% 13.2V 70% 13.1V 40% 13.0V 30% 12.9V 20% 12.8V 17% 12.5V 14% 12.0V 9% 10.0V 0%
12V 100Ah LiFePO4 batteries are currently some of the most popular for off-grid solar power systems. They’re a drop-in replacement for 12V lead acid batteries, and a great upgrade.
They are fully charged at 14.6 volts and fully discharged at 10 volts. They are made by connecting four 3.2V LiFePO4 cells in series.
Voltage Capacity 29.2V 100% (charging) 27.2V 100% (resting) 26.8V 99% 26.6V 90% 26.4V 70% 26.2V 40% 26.0V 30% 25.8V 20% 25.6V 17% 25.0V 14% 24.0V 9% 20.0V 0%
24V lithium iron phosphate batteries are another popular option for solar power projects. You can either buy an off-the-shelf 24V battery or pick up two 12V batteries and connect them in series to make a 24V battery bank.
They are fully charged at 29.2 volts and fully discharged at 20 volts. They are made by connecting eight 3.2V LiFePO4 cells in series.
Voltage Capacity 58.4V 100% (charging) 54.4V 100% (resting) 53.6V 99% 53.2V 90% 52.8V 70% 52.4V 40% 52.0V 30% 51.6V 20% 51.2V 17% 50.0V 14% 48.0V 9% 40.0V 0%
48V is more popular for larger solar systems. They rarely make sense for small-scale projects.
They are fully charged at 58.4 volts and fully discharged at 40 volts. They are made by connecting 16 3.2V LiFePO4 cells in series.
Voltage Capacity 3.65V 100% (charging) 3.4V 100% (resting) 3.35V 99% 3.33V 90% 3.3V 70% 3.28V 40% 3.25V 30% 3.23V 20% 3.2V 17% 3.13V 14% 3.0V 9% 2.5V 0%
Individual LiFePO4 cells have a nominal voltage of 3.2 volts. They are fully charged at 3.65 volts and fully discharged at 2.5 volts.
You can buy individual LiFePO4 battery cells online. They’re best used for making your own lithium batteries. You can connect cells in series and parallel to make LFP batteries with your desired voltage and capacity combinations.