Lithium Iron Phosphate (LiFePO4) batteries are becoming a popular choice thanks to their safety, durability, and eco-friendliness. To get the most out of these batteries, it’s important to grasp how the State of Charge (SOC) relates to voltage. In this article, we’ll break down the SOC vs. voltage chart, discuss the ideal SOC for lithium batteries, determine the best float voltage for LiFePO4, and look at discharge and maximum charge voltages.
What is SOC and How is it Measured?
The State of Charge (SOC) of a battery indicates its current charge level compared to its total capacity, typically expressed as a percentage. A fully charged battery is at 100%, while 0% means it’s empty. Although you can estimate SOC using voltage readings, keep in mind that this relationship isn’t perfectly linear.
SOC vs. Voltage Chart for LiFePO4 Cells
For LiFePO4 batteries, the SOC vs. voltage chart shows a relatively stable voltage throughout much of the discharge cycle. This stability means that the voltage remains consistent until you get close to either full charge or full discharge. Here’s a rough breakdown of voltage levels at various SOC percentages:
- 100% SOC: About 3.65V
- 80% SOC: Around 3.30V
- 50% SOC: Approximately 3.20V
- 20% SOC: Roughly 3.00V
- 0% SOC: Close to 2.5V
Understanding this relationship helps you keep an eye on your battery’s health and performance.
SOC VS voltage chart for LF105. EVE 3.2v 105Ah cell
Volt VS SOC For LiFePo4 cells
EVE LF105 3.2V 105Ah LiFePO4 Lithium Battery Rechargeable Lithium Battery Cells With Original QR Code Grade A
EGbatt provide 3.2V 105Ah high-power Lithium iron phosphate LiFePO4 prismatic cell which has long cycles for used for electric vehicles, golf cart, solar system, energy storage system, yacht, etc.
ANC IFP48173166-165AH 3.2v LiFePo4 cell
What is the Optimal SOC of a Lithium Battery?
For lithium batteries, including LiFePO4, the sweet spot for SOC is usually between 20% and 80%. Staying within this range helps extend the battery’s lifespan and reduce degradation. Frequently cycling between 0% and 100% can lead to faster capacity loss. So, it’s best to recharge before hitting 20% and to avoid charging to 100% unless absolutely necessary.
What is the Best Float Voltage for LiFePO4?
Float voltage refers to the voltage level at which a fully charged battery is maintained. For LiFePO4 batteries, the ideal float voltage is between 3.4V and 3.45V per cell. This voltage keeps the battery topped off without risking overcharging, which can diminish its lifespan and create safety issues.
What is the Voltage of LiFePO4 Cell Discharge?
The discharge voltage of a LiFePO4 cell varies depending on the SOC. As noted, a fully charged cell sits at about 3.65V, while it drops to around 2.5V when fully discharged. It’s crucial to avoid discharging below 2.5V, as doing so can cause permanent damage and reduce capacity.
What is the Max Charge Voltage of LiFePO4 Cell?
The maximum charge voltage for a LiFePO4 cell is generally about 3.65V. Charging beyond this can lead to overcharging, posing safety risks and shortening the battery’s lifespan. It’s important to use a charger specifically designed for LiFePO4 batteries to ensure the voltage stays in check.
Conclusion
By understanding the SOC vs. voltage relationship for LiFePO4 batteries—along with the ideal SOC, float voltage, discharge voltage, and maximum charge voltage—you can maximize your battery’s performance and lifespan. Following these guidelines ensures that your LiFePO4 batteries run safely and efficiently, providing reliable power for your needs.
