So I have 2 deep cycle batteries hooked up to a selector switch. The positives of each battery go to 1 and 2 on the switch and the negatives of the batteries are connected together and then to my trolling motor line. The output on the switch goes to 6 gauge wire that goes back to a post block that I made. There is also the negative which is 6 gauge that goes to the post block as well. I did this because of the distance I had to cover plus I can also easily disconnect the alligator clips on the trolling motor from the post block. I used 5 gauge wire for the positive and negatives from the batteries to the selector switch. I will never be using the both option on the switches I have a completely separate starting battery. I also run my depth finder and stereo off these batteries as well. But I have a kill switch that everything goes through first before it goes to the fuse box and then the accessories. My question is can I charge from the trolling motor post block backwards through the selector switch to either battery 1 or battery 2 as long as that kill switch is off for the accessories and the trolling motor is unhooked. I realized I would be charging through 6-gauge wire and then through the switch and then through 5 gauge wire but I don't think that would be a big problem. It's hard to get it at the batteries so I don't want to have to charge directly to each battery. And I am assuming that it does not matter that the two batteries are connected by the negative cable. Please see diagram a picture is worth a thousand words and shows exactly how my setup is. I don't see why it wouldn't work to charge One battery at a time through the selector switch I just want some confirmation so I don't ruin anything. Thank you
