Li-ion Battery Protection ICWhere does the effect mainly manifest?

In addition to the lithium battery protection ICs' functions such as overcharge protection, overdischarge protection, overcurrent protection, and short-circuit protection, there are also other new functions of lithium battery protection ICs.

High-precision Charging Protection

When lithium-ion batteries are overcharged, to prevent internal pressure from rising due to temperature increase, it is necessary to disconnect the charging state. The protection IC will monitor the battery voltage, and when overcharge is detected, the overcharge detection power MOSFET will disconnect and stop charging. At this point, pay attention to the high-precision detection voltage for overcharge. When charging the battery, users are very concerned about charging the battery to full capacity. At the same time, safety issues must be considered. Therefore, when disconnecting the charging state, the allowed voltage must be reached. To meet both conditions simultaneously, a high-precision detector is required. The detector's current accuracy is 25mV, and this accuracy needs further improvement.

2. Reduce power consumption of protection ICs

As the usage time increases, the voltage of a rechargeable lithium-ion battery will gradually decrease, potentially falling below the specification's regulated value, at which point it requires charging. If you continue to use it without charging, it may lead to the battery becoming unusable due to over-discharge. To prevent over-discharge, the protection IC must monitor the battery voltage. Once the voltage reaches or falls below the over-discharge detection level, the power MOSFET on the discharge side must be disconnected to stop discharging. However, at this point, the battery still has the natural discharge and current consumption of the protection IC, so it is necessary to reduce the current consumption of the protection IC to the lowest possible level.