This is a marine application but I thought I might get more reads and knowledge if I put it here. The Interstate group 27 deep cycle battery in my boat called it quits last fall. It didn't owe me a thing as i have had it for eight years. I purchased an AGM replacement for it yesterday and put it on the charger prior to installing it in the boat. After careful thought I wonder if I made a wise choice. My starting battery is a regular lead battery. I have an on board smart battery charger that connects to both batteries and is tuned on whenever I am not on the boat. Is it wise to have two different battery types on the same onboard charger and would each be fully charged?