BQ24781

The BQ24781 is a high-efficiency, hybrid power boost mode battery charge controller IC designed for laptops and portable devices. It manages charging for 1- to 4-cell lithium-ion battery packs, supports simultaneous adapter and battery power for high-performance needs, and features advanced safety protections such as overcurrent, overvoltage, and processor hot monitoring.

The BQ24781 is closely related to the BQ24780S and can often be used interchangeably in many laptop motherboards, as they share similar pinouts and SMBus addresses. However, there are minor differences in switching frequency and internal configuration. In practice, users have successfully replaced BQ24781 with BQ24780S and vice versa, but for best results, always check your device’s specific requirements. If the original chip has an “S” suffix (like BQ24780S), it is recommended to replace it with a chip of the same suffix for full compatibility.

Professional installation required. This chip should only be installed by an experienced technician with microsoldering skills. Improper installation may further damage your logic board and void your warranty.