How to Charge a Lifepo4 Battery?

02/17/2022

How would I charge a lithium iron phosphate battery? This is quite possibly the most well-known inquiries we get from our clients. The response is straightforward: utilize a LiFePO4 battery charger, obviously. While charging LiFePO4 batteries, ensure you are not involving a charger for other lithium-particle synthetic substances that are ordinarily intended for higher voltages than what is expected for LiFePO4. We are frequently inquired as to whether we can utilize a lead-corrosive battery charger to charge LiFePO4. The short response is indeed, the same length as the voltage is set inside the boundaries OK for lithium iron phosphate batteries.

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 charged at high or low temperatures. All LiFePO4 batteries are equipped with an internal BMS that protects the battery from low and high temperatures. If the BMS is disconnected due to low temperatures, the battery must warm up before the BMS can reconnect and receive charging current. If the BMS is disconnected due to high temperatures, the battery will need to cool before the BMS will accept a charge to the battery. Refer to the datasheet for your specific battery for BMS low and high temperature cutoff and reconnection values.

Our LT series lithium batteries can be charged and discharged from -20°C to 60°C. low temperature (LT) lithium batteries are cold weather rated and designed for the cold climate of Canada. These batteries have a built-in heating system that uses proprietary technology to draw power from the charger. No additional components are required. The entire process of heating and charging is completely seamless. The heating system is automatically activated when attempting to charge below 0°C and is automatically deactivated when no longer needed. Instead of drawing power from the battery, the heating system draws power from the charger, ensuring that the Li-ion battery does not discharge itself and remains powered. Simply plug the LT lithium battery into the LiFePO4 charger and the internal heating and monitoring system does the rest.

Charger Inspection

Before using the LiFePO4 charger, check that the charger cable is insulated and not broken. The charger terminal connectors should be clean and properly mated to the battery terminals to ensure a good connection and optimal conductivity. For proper torque settings, refer to the user manual or the data sheet for your specific battery.

Charging Guidelines

If the LiFePO4 battery is not fully discharged, it does not need to be recharged after each use. LiFePO4 batteries will not be damaged in the partial state of charge (PSOC). You can recharge LiFePO4 batteries after each use or after they have been discharged to 80% DOD (20% SOC). If the Battery Management System BMS) disconnects the battery due to low voltage (voltage will be <10V), remove the load and charge the LiFePO4 battery immediately with the LiFePO4 battery charger.

CHARGING LIFEPO4 IN PARALLEL

While associating LiFePO4 batteries in equal, kindly ensure every battery is inside 0.1V of one another prior to placing them in assistance, This will limit the opportunity of awkwardness between batteries. Assuming that you're charging 12V LiFePO4 batteries, the charging voltage ought to be between 14V - 14.2V. While charging 24V batteries in equal, the charging voltage ought to be 28V - 28.4V. Charging 36V lithium batteries in equal requires a voltage of 42V - 42.6V. At last, charging 48V LiFePO4 batteries require voltage boundaries of 56V - 56.8V. The following is a table with a synopsis showing the voltage necessities for every framework voltage.

 

System VoltageCharging parameters
12V14V – 14.2V
24V28V – 28.4V
36V42V – 42.6V
48V56V – 56.8V

 

The voltage boundaries apply to both charging profiles CC and CC-CV. On the off chance that your charger's voltage is lower than those recorded in the table, it won't harm your battery, yet it will be undercharged, and it won't give the full appraised limit of the battery. Assuming your charger's voltages are higher than those recorded in the tables over, the BMS might disengage the battery and you might need to eliminate the heap to reconnect. We prescribe you supplant the charger to stay away from this bother and to put resources into an excellent LiFePO4 battery charger.

CHARGING LIFEPO4 BATTERIES IN SERIES

While interfacing batteries in series, kindly ensure every battery is inside 50mV (0.05V) of one another prior to placing them in assistance. This will limit the opportunity of an awkwardness between batteries. Assuming your batteries escape balance, the voltage of any battery is >50mV (0.05V) from one more battery in the set, you should charge every battery separately to rebalance. You can charge every battery separately intermittently to stay away from unevenness. While charging LiFePO4 batteries in series, it is ideal to utilize a multi-bank charger that charges every battery exclusively to guarantee the cells stay adjusted. You can likewise utilize a 24V battery LiFePO4 charger or a 48V battery LiFePO4 charger assuming that you might want to charge your framework overall.

CHARGING LIFEPO4 WITH AN INVERTER/CHARGER AND/OR CHARGE CONTROLLER

The following are the key, average charger inputs while utilizing an inverter/charger or charge regulator for charging LiFePO4 batteries. Numerous all in one inverter/chargers require extra boundaries, kindly contact specialized help for help. LiFePO4 batteries don't need leveling. LiFePO4 batteries don't need temperature remuneration for voltage while charging at hot or cold temperatures.

 

PARAMETER12V SYSTEM24V SYSTEM48V SYSTEM
Bulk Voltage14V – 14.6V28V – 29.2V56V – 58.4V
Absorption Voltage14V – 14.6V28V – 29.2V56V – 58.4V
Absorption Time0- 6 min0- 6 min0- 6 min
Float Voltage13.8V ± 0.2V27.6V ± 0.2V55.2V ± 0.2V
Low Voltage Cutoff10V20V40V
High Voltage Cutoff14.629.2V58.4V

CHARGING LIFEPO4 WITH ALTERNATOR AND DC TO DC CHARGERS

Contingent upon the nature of the alternator, it might turn out great to charge LiFePO4 batteries without changes. In any case, inferior quality alternators with unfortunate voltage guideline can make the BMS disengage LiFePO4 batteries. Assuming that the BMS detaches the batteries the alternator might be harmed. To safeguard your LiFePO4 battery and alternator, if it's not too much trouble, make certain to utilize a viable great alternator or introduce a voltage controller. You can likewise utilize a DC to DC charger to securely and really charge your batteries including house banks. Introducing a DC to DC charger is the prescribed choice with regards to accusing lithium of an alternator.