I have two 12v lead acid batteries on my boat. One at the front for the trolling motor (~80 AH) and 2 smaller batteries in parallel at the rear for electronics (~30-35 AH combined).
I want to put a solar panel on my garage, so I can hook the batteries up when I get back from the lake to recharge them and to keep them maintained. I only need a 30 or 50 watt panel to charge both battery banks, since I never use full capacity and usually have at least couple days between trips. Instead of buying 2 smaller panels, one for each battery bank, I was thinking about hooking up 2 charge controllers to the same solar panel.
The solar panel disconnect switch is required because the batteries should be connected to the charge controllers before the solar panel is connected. On my boat, I would add DC plugs for both batteries to connect the charge controllers.
I think this will work fine, but I have done a lot of searching and could not find any information about connecting multiple charge controllers to the same solar panel. I am aware they make dual battery charge controllers, but they don't look any better than the $10 units you can find on Amazon and they are more than double the price.