The two solar panels have been given independent 10A regulators/chargers to which leisure batteries are attached.
The output of PV#2 charges accumulator #2 and is intended for non lighting power via Bus #2.
PV#1 intended for lighting charges accumulator #1 which in turn powers bus #1. The power for Bus#1 can be switched to an internal 12V5A supply that can be used to supplement the solar charger supply during battery maintenance of periods of prolonged use.
This uses a simple latch in order to perform the switch between supplies, the external supply can be activated via the NO switch which in turn activates the latch. This is held on using the voltage originating from the 12V mains supply but again this can be interrupted by depressing the NC switch.
The advantage of this, is that should the mains supply fail the power holding the latch closed will also be lost causing the source for Bus #1 to drop back to battery supply.
Lamps and voltage indicators are also included on the design in order to show the operation state of the panel.