You really have to decide what you are doing with your second battery before you jump to conclusions. I just added a second battery. I added a Perko switch. I have no intention of using my second battery for anything other than a backup start battery. I'll keep it charged. We usually park the boat to hang out and run the stereo from 20-60 min. before we power up and run again. You have to develop your typical profile and decide your battery setup based on the same info. Mine was easy. Don't be a fool either way.