I have had terrible luck with everstarts and its sister brand batteries over the years, in cars, boats, motorcycles etc. For me its bad enough that i will never ever run them again even in my lawn mower.
I run a much better quality wet cell deep cycle now(trojan) and i have had not a single issue. My last set went 6 years and were still good (good as in 8+ hours of full power on a windy day good) when i traded the boat in.