Detection method for the protection board of lithium battery pack

Many people don't understand the purpose of the lithium-ion battery protection board. The lithium-ion battery protection board, as the name implies, is used to protect the lithium-ion battery pack. The purpose of the lithium-ion battery protection board is to protect the battery from over-discharge, over-charge, over-current, and output short-circuit protection.
The lithium-ion battery protection board is mainly used to protect the charging and discharging of the lithium-ion battery pack. When fully charged, it can effectively ensure that the voltage difference between each single lithium-ion battery is less than its set value, realize the balanced charging of each single battery of the lithium-ion battery pack, and effectively improve the charging effect of the lithium-ion battery pack composed of series and parallel connections.
At the same time, the protection board can also detect the overvoltage, undervoltage, overcurrent, short circuit, and overtemperature status of each single lithium-ion battery in the lithium-ion battery pack. After detecting these states, the protection board can adjust and warn in time. The protection board can effectively protect and extend the service life of the lithium-ion battery pack.
The purpose of the undervoltage protection is to prevent the individual lithium-ion cells in the lithium-ion battery pack from being damaged due to over-discharge during discharge.
Protection board good or bad detection method:
1. Detection circuit
Li-ion battery packs produced by different manufacturers have different protection boards with different functions. Some protection boards are designed with thermistors for overheating protection of lithium-ion battery packs.
The thermistor on the protection board is only a temperature sensor for the external circuit. If the protection board circuit is in poor contact, the lithium-ion battery is easily damaged. Therefore, checking the circuit of the protection board is an important first step for us to detect the protection board.
2. Cable
Use a multimeter to confirm the correctness of the cable connection. By pressing the B-line terminal with the black test lead of the multimeter and pressing the B1 line terminal with the red test lead of the multimeter, the voltage of the first string of batteries is obtained. In this way, all series and parallel batteries in the lithium-ion battery pack are measured.
If the wiring of the cable is correct, and the power difference of all battery strings is lower than a certain value, it means that the protection board has played a role to ensure the consistency of all batteries in the lithium-ion battery pack.
3. Measure the voltage
After measuring the voltage of the lithium-ion battery pack and confirming that it is normal, plug the cable into the protection board and measure the resistance between the ports on both sides of the protection board. If the resistance is zero, it means that the lithium-ion battery pack is unimpeded and the protection board has a good function.