What is a battery protection chip?
Lithium-ion batteries are generally composed of a battery cell, a battery protection plate and a casing, of which the protection plate contains the battery protection chip. In the normal use of lithium-ion batteries, the internal chemical reaction of electrical energy and chemical energy conversion, but under certain conditions, such as over-charging, over-discharging and over-current will lead to chemical side reactions inside the battery, the side reaction intensified, will seriously affect the performance and service life of the battery, and may appear a large amount of gas, so that the internal pressure of the battery rapidly increase and then explode, resulting in safety problems. Therefore all lithium-ion batteries have to a protection circuit, that is, the battery protection chip, used for the battery charge, discharge state for effective monitoring, and under certain conditions to shut down the charge, discharge circuit to prevent damage to the battery civet ion battery.
Overcharge protection: When the charger charges the battery, the battery voltage will rise slowly, when it reaches Vdet1, the protection IC will act, at this time the level of Cout will turn from high to low, so that the charger can not continue to charge the battery, thus achieving a protective effect.
Over-discharge protection: When the battery is discharged through the load, the cell voltage will continue to fall below Vdet2, the protection IC will act to protect the battery, at this time the Dout pin will change from high level to low level, thus shutting down the Mosfet so that the cell cannot continue to discharge the load.