Working steps of lithium battery protection board

The lithium battery protection board is mainly composed of protection IC (overvoltage protection) and MOS tube (overcurrent protection), which is used to protect the safety of lithium battery cells. Lithium batteries have been widely used because of their large discharge current, low internal resistance, long life, and no memory effect. Today, Guoren Chuangfa will learn the working steps of lithium battery protection board with everyone.

1. Voltage protection capability

Overcharge protection: the protection board must have the ability to prevent the cell voltage from exceeding the preset value. Overdischarge protection: the protection board must have the protection against the bottom of the cell voltage The ability to be at a preset value.

Second, current capability (over-current protection current, short-circuit protection)

As a safety protection device for lithium batteries, the protection board must be in the normal state of the equipment It can work reliably within the working current range, and it must act quickly when the battery is accidentally short-circuited or over-current, so that the battery cell can be protected.

Three, on-resistance :

Definition: When the charging current is 500mA, the on-resistance of the MOS tube. Due to the high working frequency of communication equipment, the low bit error rate required for data transmission, and the steep rising and falling edges of the pulse train, the current output capability and voltage stability of the battery are required to be high, so the MOS switch of the protection board is turned on The time resistance should be small. The single-cell battery protection board is usually less than 70mΩ. If it is too large, it will cause the communication equipment to work abnormally, such as the sudden disconnection of the mobile phone during a call, the phone cannot be connected, and noise.

Four. Self-consumption current

Definition: IC working voltage is 3.6V. Under no-load condition, the working current flowing through the protection IC is generally Very small. The self-consumption current of the protection board directly affects the standby time of the battery. It is usually stipulated that the self-consumption current of the protection board is less than 10 microamps.

Five, mechanical properties, Temperature adaptability and antistatic ability

The protection board must be able to pass the vibration and impact tests specified by the national standard; the protection board can work safely at -40 to 85 degrees, and can withstand the non-contact ESD static test of ±15KV.

The promotion of lithium battery industry chain enterprises, lithium grid (li-b.cn) welcomes contributions.