This is the third generation power control board in our van. The first and second design worked but I have tried to simplify the controls. I am a novice when it comes to electronics however building these boards have been essential to photography on the road, as camera batteries and laptops always need charging. Unfortunately, I may have oversimplified it as switching on either battery now appears to connect both batteries together via the amp meter. I am not sure if there is an alternative button wiring or a fix with diodes, and if so which type of diodes? Any suggestions?
Update: The Mark Four
