The Batrium WatchMon can support 8-30V power supply.
If required to power the WatchMonCORE (version 4.5) above 30Vdc (i.e. 48V pack voltage), we recommend always connecting the supervisor supply to a DC-DC (ideally, 24Vdc) to ensure a robust, long-term, and reliable product.
USB provides normally around 5V so is, therefore, sufficient for the initial setup step but not for permanent use. Initial Setup is normally done using just the USB to power the WatchMon. This allows you to configure and test your system before using it to power the WatchMon.
If your battery is outside of the 8-30V range, such as is common with EVs then usually a 12V battery is used to power the WatchMon.
If your battery is within the 8-30V range, then commonly the battery itself is used to power the WatchMon.
The power supply should stay connected if you are just configuring information using a USB connection.
Always disconnect your battery pack from the WatchMon (both power pins and CMU) before starting any rewiring task. This is to prevent you from damaging the WatchMon. If you cause a power spike during rewiring, then it will go up the line damaging any electronics attached.
The WatchMon supervisor does not need to be continually connected to a PC in order to function. They will still monitor, communicate with inverters, trigger a circuit breaker, etc. based on its setup.
We do not recommend that they be permanently powered via the USB (5V) except during setup and firmware updates.
For normal use, it is best practice to be powered via the 2-pin supply connector (8-30V).