In order to download files in the field:
Do we need to set the switch to the USB/OFF position before removing the SD?
In either case, once the SD is copied and files deleted, and then the SD is inserted back in the unit, is the configuration kept or should we run the configuration app again?
In case we change batteries, is the configuration lost?
You should switch to USB/OFF before removing the SD card as that will allow the AudioMoth to close any files correctly if it is writing whilst the SD card is removed. The configuration is persistent on the AudioMoth even if the batteries are removed. However, the time is not maintained if the batteries are removed so if you change the batteries, and then switch back to CUSTOM, the AudioMoth will enter acoustic configuration mode waiting for you to set the time with the smartphone app before it will start making recordings. As an alternative, you can use the Time App to set the time without changing the existing configuration. Or use the Config App to update both the configuration and the time. Alex