I'm installing a second battery as a house battery to run the auto pilot etc. I will run both batteries through a
four position switch. I will continue to use the keyed isolating switch.
All switches are on the positive side.
The negative goes straight from the terminal to the engine block.
The batteries are side by side. If I join the neg ot the second battery to the neg terminal of the first battery
and hook both the positives to the battery switch, when I put the switch on BOTH, am I still on 12v or is it
now 24v.