Hi
@Petunia and welcome to the site. Just from your brief write up it's obvious you have real battery problems and those problems stem from your lack of knowledge about batteries. Please don't be offended but you don't even know what questions to ask.
But that's not a problem because you are every bit as capable as the rest of us to learn what you need to know to keep your batteries healthy.
Here are a few primers you may want to start out with:
Light Cycle vs. Deeper Cycle NOTE: This article deals with FLOODED marine batteries, not AGM or GEL batteries. The Problem: The problem, as I see it, is one of dishonest marketing where multiple battery types wear the same clothes (sticker) and will perform differently when
marinehowto.com
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See videos #1, 4, and 9 in the Trojan web page.
I know they are a little heavy on theory but just look at the basics such as amp-hours, depth of discharge, and required charging.
It's just part of boating, much the same as "safety on the water".