How to choose a lithium-ion battery protection board?
The lithium battery protection board is divided into a software battery protection board BMS and a hardware battery protection board BMS. The hardware protection board has low cost and is widely used, but its functions are limited.
The purpose of the protection board is to protect the battery from overcharging and overdischarging, to prevent high current from damaging the battery, and to balance the battery voltage when fully charged.
Note: Lithium polymer batteries BMS, lithium ion batteries BMS, and lithium iron phosphate BMS battery protection board shells are generally made of metal to facilitate heat dissipation; when installing the protection board, insulation between the battery and the battery must be done.
What are the differences between the batteries protection boards?
According to the different types of charging and discharging ports:
1. Common port protection board: The same connection port is used for charging and discharging. From the outside, there are two external wires.
Advantages: convenient wiring, no wrong connection between the charging port and the discharging port, and cheaper prices. Disadvantages: charging and discharging use the same MOS tube to heat up quickly.
2. Seperate port protection board: different connection ports are used for charging and discharging. From the outside, there are at least three external wires.
Advantages: different connection ports are used for charging and discharging, the MOS tube has a long service life and the temperature will not be too high.
Disadvantages: The cost is high, and the charging and discharging ports are easily connected incorrectly, the consequence is that there is no protection for the battery pack.
According to the battery material type:
1. Ternary lithium battery protection board; nominal voltage 3.7V
2. Lithium iron phosphate battery protection board: nominal voltage 3.2V
3. Lithium titanate battery protection board: nominal voltage 2.4V
The parameters that the protection board needs to refer to
1. Number of battery cell series
2. Common or seperate port for charge and discharge
3. Charge termination voltage (number of battery cell strings * cell charge termination voltage)
4. Discharge termination voltage (number of battery cell strings * cell discharge termination voltage)
5. Discharge current (the limit current of the protection board when discharging, the larger the current, the more expensive the price)
6. Charging current (the limit current of the protection board during charging, the charging time is 5-8 hours, which should be greater than the charger current, otherwise overcharge protection)
7. Equilibrium function (mark with or without, most of them are passive equilibrium, the price of active equilibrium is too expensive)
8. Communication function
9. Battery temperature control function (with NTC sensor)
10. Self-consumption of protection board (20-100 microampere)
12. Size (length*width*height)