I'm going on a week long dry camping trip next week and was thinking of adding a 12V deep cycle and maybe a 12V starting battery to my existing dual 6V golf cart battery setup. Has anyone else mixed battery styles/voltage before and had issues?
Run the 12V for whatever and use the 2-6V for whatever. You just can't run them at the same time. Better to isolate. It's not good to have new and old on the same circuit.