Does anyone know the IC used for for the battery charging circuit?
The schematic just labels it as U1 and does not give a part number.
I want to use a secondary 4.5V power supply (not a battery) to power the board when USB is not plugged in, so I planned on connecting it to the battery pads. This is higher than a battery’s typical voltage, so I just want to make sure it’s safe to do so. The 3.3V LDO regulator circuit looks like it would work with a 4.5V power supply, but I can’t confirm that the battery charging circuit won’t explode when 4.5V is applied to the battery voltage because I don’t know what IC it is.
Any help would be greatly appreciated.