Charging Lithium Iron Phosphate (LIFEPO4) Batteries
How do I charge a LiFePO4 battery? This is one of the most common questions we get from our customers. The answer is simple: use a LiFePO4 battery charger, of course. When charging LiFePO4 batteries, make sure you are not using a charger for other lithium-ion chemicals that are typically designed for higher voltages than what is required for LiFePO4. We are often asked if we can use a lead-acid battery charger to charge LiFePO4. The short answer is yes, as long as the voltage is set within the parameters acceptable for LiFePO4 batteries.
Charging Guidelines
LiFePO4 batteries do not need to be recharged after each use if they are not fully discharged. liFePO4 batteries are not damaged when they are in the partially charged state (PSOC). You can charge the LiFePO4 battery after each use or after it has been discharged to 80% DOD (20% SOC). If the Battery Management System BMS) disconnects the battery due to low voltage (voltage will be <10V), use the LiFePO4 battery charger to remove the load and recharge immediately.
Charging Temperature
LiFePO4 batteries can be safely charged between 0°C and 45°C (32°F and 113°F). LiFePO4 batteries do not require temperature compensation for voltage when charging in high or low temperature conditions. If the BMS is disconnected due to low temperatures, the cell must warm up to allow the BMS to reconnect and receive charging current. If the BMS is disconnected due to high temperature, the battery needs to cool before the BMS can accept the battery charge. For BMS low and high temperature disconnect and reconnect values, refer to the data sheet for the specific battery.
How to Charge LIFEPO4 Batteries with Lead-Acid Chargers
Most lead-acid battery chargers can be used with LiFePO4 batteries as long as they fall within the appropriate voltage guidelines. Liquid-rich battery charging algorithms typically have voltages higher than the LiFePO4 charging requirement, which will cause the BMS to disconnect. If this happens, it is often good practice to replace the charger with a LiFePO4 charging profile. Since the BMS protects the battery, using a lead-acid charger will not normally damage the battery.
Note that if the BMS is disconnected due to low voltage, the lead-acid battery charger may not be able to reconnect the BMS, even if the charger has acceptable charging parameters to charge LiFePO4. This is because when the BMS is disconnected, the LiFePO4 battery has no voltage and the voltmeter reads 0V, while the lead-acid charger needs the battery to read voltage to start charging. If the battery reads 0V, the lead acid battery charger will not recognize that the battery is connected and should start charging. This is also true for some low quality Li-ion battery chargers. It is always recommended that you invest in a high quality LiFePO4 charger to ensure high performance and longevity.
评论
发表评论