What is a lithium battery protection board?

The lithium battery protection board is a protection for the charging and discharging of the series lithium battery pack; when fully charged, it can ensure that the voltage difference between the individual cells is less than the set value (generally ±20mV), and realize the equal charge of the individual cells of the battery pack , Which effectively improves the charging effect in the series charging mode; at the same time, it detects the overvoltage, undervoltage, overcurrent, short circuit, and overtemperature status of each single cell in the battery pack to protect and extend the battery life; undervoltage protection makes every A single-cell battery is used to prevent damage to the battery due to over-discharge.

The finished lithium battery consists of two main parts, lithium battery core and protective plate. The lithium battery core is mainly composed of positive plate, diaphragm, negative plate and electrolyte; positive plate, diaphragm, negative plate are wound or laminated, packaged, and filled with electrolyte , The battery cell is made after packaging. Many people don’t know the role of the lithium battery protection board. The lithium battery protection board, as the name suggests, is used to protect the lithium battery. The lithium battery protection board protects the battery Flow, there is output short-circuit protection.

Why do some lithium battery protection boards need to be activated？

Now not all lithium battery protection boards need to be activated, but some protection ICs need to be activated, and this is the old IC solution, the old IC solution. So this is necessary to make the protection board not work to reduce static electricity. Discharge energy so that the lithium battery can be stored longer. This is why the design requires charging activation.

The field effect transistor used in the lithium battery protection board is used as the protection element. In order to ensure that the battery will not be reconnected to the circuit when abnormal, the circuit is specially designed. The method is that the power supply of the control part of the protection circuit is the power supply behind the protection field effect tube, and the circuit will only work after the protection tube is normally turned on. Therefore, when it is used for the first time or after protection has been generated, the protection circuit cannot work because the power supply of the subsequent circuit is disconnected and the circuit has no power supply. There is no output from the battery. At this time, only when the battery is connected to the charger, the charger is used to supply power to the control circuit part of the protection circuit, and the control part is energized to work, the battery can be used normally.

How to activate the lithium battery protection board

If the protection board needs to be activated after charging or completely disconnecting the load due to current limiting protection, it is relatively troublesome, but you can also short-circuit B- (battery negative) and P- (discharge negative). The protection will be released. Remember not to carry a large load when shorting the connection (such as turning it and twisting it all the time), otherwise there may be a lot of sparks. The fundamental reason is that a large pressure difference is formed at both ends of the discharge MOS after the protection. , A short-circuit touch is to directly reset the DS level of the discharge MOS to 0V, and the protection is released at this moment.