Boat Batteries have always been a big bugaboo for me. I have been told never start an engine w/ an ECM w/ a deep cycle battery, because there isn't enough voltage and low voltage can fry your ECM. I have two 8D batteries one for my start battery and one for the house. I decided to go w/ a starting battery for the house in case I needed it to start my main in the event my start battery was down. My problem is when I run my house battery down it doesn't wanna come back. Now I'm thinking of going to a deep cycle for the house, but it seems like every deep cycle I've ever had doesn't recover fully either. Is it my battery brand? I use Interstate "workaholics" mainly because thats what Redden Net sells in Cordova. I'm sick of lugging 8D's around every spring! Any thoughts?