What is the principle that the laptop battery is locked?

The laptop battery will self-discharge even if it is not used, so even if the fully charged battery is not used for a long time, this situation will occur. In order to prevent the battery from being permanently damaged due to continued discharge when the battery is too low, the battery protection chip will be locked, causing the notebook to not recognize the battery, unable to charge and discharge, etc.

When the voltage of the lithium battery is too low, the battery performance will be seriously damaged. The lithium battery is inherently self-discharged [the voltage will gradually decrease with time], so the notebook battery has a monitoring chip, and once the voltage is too low, it will be written. Inside the eeprom, the forced battery cannot be output. This is called self-locking. The so-called unlock is to refresh the eeprom settings, in order to open the output [also charge input] line, replace the board to recover. However, the battery has a long life, and the official details of all monitoring chips are not open.

Laptop battery protection board, which is a piece of circuit board based on SMB1.1 agreement, with functions of energy management and charging and discharging management functions.

The protection board is a circuit board based on the SMB1.1 protocol, and has three chips on it: a battery metering management chip, a charge and discharge management chip, and a serial EEPROM memory chip.

Positive protection plate is equipped with laptop batteries metering chip and charge and discharge management chip.

Laptop battery protection board on the back of the block is equipped with a serial EEPROM memory chips.

Decrypting and unlocking the laptop battery protection board are two different jobs. To put it simply, the battery management system can only be decrypted before the battery management system is unlocked. Only unlock of battery management system can change the battery parameters and the use of information. If you only change the battery and do not unlock it, you will not be able to achieve satisfactory results (for example, the battery can only be charged to the last full charge capacity recorded, and the battery management information will show the number of times used before the repair).

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