I haven't had any battery problems yet on my defender after 1 year. It seems to have a really good stator in it and keeps up with all my lighting I'm running without draining the battery. I do however have 2 seadoos that use the 30ah batteries and I have not had good luck with the ETX30LA. I believe it goes under a lot of brands at different stores but has that same part number. I have tried everything with all the small batteries i have, from battery minders to solar panels to bringing them in in the winter and they just don't seem to last very long. The flooded type that are cheaper seem to last longer than the AGM and cost about half as much. I get about a year and half from the agms and three years out of the flooded. I'm thinking i need to just buy the cheapest flooded battery I can find and replace it at 2 years or when it starts to struggle.