Hello! I am interested, are AudioMoth devices compatible with external power supply or only with batteries?
You can power the AudioMoth through the USB socket. However, many cheap power supplies don't provide very smooth power and sometimes switch off automatically as they don't register the very low power that the AudioMoth consumes when asleep. You can also supply the board from another battery by soldering onto the two power supply connectors on the top of the PCB where the battery holder is connected (you can also remove the battery holder). Batteries up to 6V including LiPo batteries work well. You can use higher voltage batteries but the voltage regulator will get hot. See the discussion in the AudioMoth Dev application note - https://github.com/OpenAcousticDevices/Datasheets/blob/main/AudioMoth_Dev_Datasheet/AudioMoth_Dev_Datasheet.pdf.