If voltage recommendations are followed, most lead acid battery chargers will work with LiFePo4 batteries. The voltage requirements for LiFePO4 are usually met using the AGM or gel method.
The Battery Management System (BMS) usually fails because the voltage used to charge flooded batteries is higher than the voltage needed to charge LiFePO4 batteries. Use a charger that supports the LiFePO4 charge profile if this occurs. Batteries can be charged with lead-acid devices without fear of being damaged by the BMS.
Assume that the battery management system (BMS) shuts down due to insufficient voltage. In this case, even if the charger meets the allowable charging criteria for LiFePO4, the lead acid battery charger may not be able to reconnect the BMS.
The lithium battery has no voltage and the voltmeter shows 0V when the BMS is off. On the other hand, lead-acid chargers require the battery to be connected before charging. If the battery voltage is not 1, the lead acid battery charger will not know if a new battery is installed or when to start charging it. Poor quality lithium chargers also cause this problem. The highest quality LiFePO4 chargers will provide the best performance and the longest possible lifespan.
Charging LiFePO4 Battery in Parallel
To avoid overheating when using several LiFePo4 batteries in series, make sure that their voltages do not exceed 0.1 V. This will reduce the risk of battery imbalance. When charging 24 V batteries in parallel, the charging voltage must be between 28 V and 28.4 V. When simultaneously charging 36-volt lithium batteries, there should be between 42 and 42.6 volts. A voltage range of 56V to 56.8V is suggested by the LFP battery manufacturer for charging 48V LiFePO4 batteries. The voltage requirements for each system voltage are shown in the table below.
The voltage settings are used by the CC and CC-CV charging profiles. Using a charger that does not meet the minimum voltage requirements will not damage the battery. However, this will leave your battery undercharged; limiting its ability to deliver the maximum capacity it was designed for. To reconnect the battery, you need to disconnect all currently connected loads and reduce the voltage of the charger to the values shown in the tables above. We suggest replacing the charger or purchasing a high-quality LiFePO4 charger to solve this problem.
Charging LIFEPO4 BATTERIES in series
Please make sure the battery voltages are within 50 millivolts of each other before connecting them in series. Battery imbalance will be less likely. The difference in voltage between any two batteries in a set will be over 50 millivolts if your batteries become unbalanced (0.05 volts). For rebalancing, it is recommended to replenish each battery in its slot. You must regularly charge each battery in a separate compartment to avoid imbalance. Use a multi-cell charger that can charge each battery individually while charging LiFePo4 batteries sequentially to keep the cells in balance. You can use a 48V LiFePO4 charger or a 24V LiFePO4 charger to power the system. These chargers are available to you.
Last Words
The voltage requirements for LiFePo4 batteries are usually met using the AGM or gel method. Batteries can be charged with lead-acid devices without fear of being damaged by the BMS. Poor quality lithium chargers also cause this problem. Using a charger that does not meet the minimum voltage requirements will not damage the battery. However, this will leave your battery undercharged, limiting its capacity. We suggest replacing the charger or purchasing a high-quality LiFePO4 charger to solve this problem.
