Originally Posted by brokedown
I'm currently using a marine battery bank switch to manually control a connection between banks, but I have been planning to replace it with an esp32, voltage sensors, and a big solenoid to connect them automatically in the future. My experience is also that solenoids fail open.
I know you know this Josh but for the OP's info:
If you are switching between two battery banks using a single charge controller you may want to make sure that your battery switch is "make before break" .
A "break before make" variety will leave your charge controller without battery while your your panels are still connected. This can make your charge controller very unhappy.