Finally going to install a second battery in my boat and was wondering what to buy and how it works. I understand the "AFD" rating which I want, but how do I ensure both batteries are charging? Do I have to actually switch the position to "Both" to get both batteries to charge. If I connect two batteries in parallel the weakest will draw down the stronger. Is there some device out there to automatically control which battery to charge. Is it worth separating electronics from the starter battery or just keep everything as is? I don't often run anything just sitting around with the motor off. It is also my understanding that the alternator doesn't put out the full output at idle (trolling) speeds. I do a lot of trolling. I also have a 75 watt solar panel that I connect to the battery when I pull the boat out of the water.
Any advice would be helpful.
Any advice would be helpful.
