Lithium Iron Phosphate Battery Charging Basics

Lithium iron phosphate battery is a kind of lithium-ion battery that uses lithium iron phosphate as the positive material and carbon as the negative material, compared with other types of lithium-ion batteries, lithium iron phosphate batteries are becoming more and more popular due to their good performance and safety.

The single rated voltage of lithium iron phosphate battery is 3.2 volts, and the charging cut-off voltage is about 3.6 volts. During charging, some lithium ions in lithium iron phosphate are discharged and transferred to the negative electrode through electrolyte to be embedded in the carbon material of the negative electrode; at the same time, the electrons are released from the positive electrode to reach the negative electrode to maintain the balance of the chemical reaction. In the discharge process, lithium ions from the negative electrode off, through the electrolyte to the positive electrode, while the negative electrode to release electrons to the positive electrode, to provide energy for the outside world.

What you need to prepare for charging lithium iron phosphate batteries

1. Lithium iron phosphate battery charger

2. Multimeter or battery tester

3. Power supply (DC or AC)

Lithium iron phosphate battery charging steps

1. Check the lithium iron phosphate battery

Need to check the appearance of lithium iron phosphate batteries are not broken, bulging bags and other phenomena, the battery does not have any corrosion near the positive and negative electrodes, the battery should be placed in the surrounding no sparks, high temperature, to ensure that the battery is safe to run in the charging process.

2. Check the lithium iron phosphate battery charger

Before using lithium iron phosphate batteries, you need to check the insulation of the charger cable, the surface is not damaged. The charger terminal connector should be clean and able to match the battery terminals to ensure a good connection and the best conductivity.

3. Determine the charging voltage

The standard voltage of a single lithium iron phosphate battery is 3.2 volts, and our charging voltage range is between 3.5 volts and 3.65 volts. If our battery pack is 12 volts, then we need to charge the voltage between 14 volts and 14.6 volts, if the battery pack is 24 volts, we need to charge the voltage between 28 volts and 29.2 volts, because lithium-ion batteries are very sensitive to over-voltage and over-current and need to be matched with the right voltage.

4. Correctly connect the lithium iron phosphate battery

Connect the positive terminal of the lithium iron phosphate charger to the positive terminal of the battery first, and then connect the negative terminal of the charger to the negative terminal of the lithium iron phosphate battery to ensure that the positive and negative terminals are correctly aligned. Note: It is best to wear safety equipment to ensure personal life and health safety.

5.Connecting to the power supply

Connect the charger to the power supply, according to the specifications of the charger, AC or DC can be used. Then turn on the power switch and start charging the lithium iron phosphate battery.

6. Check the charging status

In the process of charging the lithium iron phosphate battery, you can use a multimeter or a battery monitor to monitor the charging process to ensure that it can be charged properly and that the voltage, current and temperature of the battery are normal during charging.

7. End charging

When the lithium iron phosphate battery is fully charged, we need to disconnect the charger immediately to prevent overcharging. (When disconnecting the charger, you need to disconnect the negative terminal first and then the positive terminal)

Charging method of lithium iron phosphate battery

When charging lithium iron phosphate batteries, no matter what type of charging method we choose (solar charging, DC charging, AC charging, etc.), we need to confirm the compatibility between the selected charger and lithium iron phosphate batteries, to ensure that the charging process is safe and optimal performance. Different types of charging methods are as follows:

1. Charging by solar energy

Using solar energy to charge LiFePO4 batteries is an environmentally friendly and sustainable method. It mainly requires the use of solar controllers, which can effectively regulate the voltage of the energy generated by the solar panels to charge the LiFePO4 battery. However, it is necessary to pay attention to the type of solar controller, generally MPPT solar controller can directly charge the LiFePO4 battery directly, PWM solar controller is mainly suitable for low power applications, MPPT solar controller is more suitable. This application is mainly used in solar off-grid systems, remote areas and environmental energy solutions.

2. Charging with AC power

You can use the alternator on the vehicle to charge the lithium iron phosphate battery, but you need to have a voltage regulator, because when you use the alternator due to poor voltage regulation, it will cause the battery management system to disconnect the lithium iron phosphate battery, which will lead to alternator failure, in order to avoid this kind of thing, we recommend using a home AC charger for charging.

3. DC charging

In RVs or large trucks and other equipment, lithium iron phosphate batteries can be connected to the vehicle alternator DC-DC charger, which can ensure that the vehicle can operate normally.

4. Parallel charging lithium iron phosphate batteries

When connecting LiFePO4 batteries in parallel, please make sure that the voltage between each battery is within 0.1 volts, and choose the right voltage to ensure a smooth charging state.

5. Series charging lithium iron phosphate batteries

When connecting LiFePO4 batteries in series, please make sure the voltage between each cell is within 0.05 volts, and then charge them. This will minimize the possibility of imbalance between cells. If the battery pack becomes unbalanced, you will need to charge each cell individually to ensure that the battery pack is balanced.

Summary

When charging lithium iron phosphate batteries, we need to pay attention to the charging steps as above, do not feel troubled, this will maximize your life, health and safety. There are many ways to charge lithium iron phosphate batteries, we have to choose the safest, to ensure our personal health and safety.