When the MPPT controller powers up upon connecting the solar panels, could it potentially switch to 24 V mode and then cook a 12 V battery that is connected only after the panels have been connected?
asked
Which battery mode (12 V or 24 V) does an MPPT charge controller switch to when no battery is connected at power-up?
The battery voltage would have to be very high (17v I think?) for the mppt to select 24v batt setting.
Likewise the mppt could set for a 12v batt below 17v (?) for a deeply discharged 24v battery.
Always pays to do things properly.
The answer is, it depends.
If the controller is brand new, it will auto-detect the voltage of the batteries.
If the controller has been used before, it will use the voltage it was previously configured as.
When going from 12V to 24V I had a controller shutdown due to high voltage, not sure what happens going from 24V to 12V......
