> It has a battery soldered on the circuit board. The battery slowly discharges while the unit is on. In about 10 years of operation, the battery voltage drops

> It has a battery soldered on the circuit board. The battery slowly discharges while the unit is on. In about 10 years of operation, the battery voltage drops below 1v or so. The battery powers nothing I am not an electrical engineer. Could the microcontroller use the battery as some kind of calibration? Or could it have another function?