Charge and discharge protection of lithium ion battery pack

Posted by sere on February 17th, 2020

Lithium ion battery pack is a widely used rechargeable battery, which has the advantages of high single operating voltage, small size, light weight, high energy density, long cycle life, fast enough charge in a short time and wide range of allowable discharge temperature. In addition, lithium ion batteries have the advantages of small self-discharge current, no memory effect and no environmental pollution. Its global supply is growing. Global supply of lithium-ion rechargeable batteries rose 17 percent in 2007 from a year earlier, according to a report by market research firm idc. With the expansion of lithium ion battery, the charge and discharge protection of lithium ion battery becomes more and more important.

Lithium ion battery protection

At present, the safety of lithium ion battery is the most concerned issue, so its protection is very important. The protection of lithium ion battery mainly includes over charge protection, over discharge protection, over current protection and short circuit protection.

Overcharge protection

When the charger overcharges the lithium ion battery, the charging state shall be terminated to prevent the internal pressure rise caused by the temperature rise. To this end, the protection device needs to monitor the battery voltage, when it reaches the battery overcharge voltage, that is, activate the overcharge protection function, stop charging.

Overdischarge protection

In order to prevent the over-discharge state of lithium ion battery, when the lithium ion battery voltage is lower than its over-discharge voltage detection point, the over-discharge protection is activated, the discharge is stopped, and the battery is kept in the standby mode of low static current.