BQ2945xy Overvoltage Protection Devices Texas Instruments BQ2945xy Overvoltage Protection Devices are secondary-level voltage monitors and protectors for Li-ion battery pack systems. Each cell on the BQ2945xy is monitored independently for an overvoltage condition. Additionally, the configuration on the devices facilitates whether the output is triggered after a fixed delay if any of the two or three cells has an overvoltage condition. This output is initiated into a high state after an overvoltage condition meets the specified delay timer.