Seems I am always learning new things. I recently learned that a traditional led acid battery will discharge about an amp a day just sitting. So if your batteries sat idle all winter you may have done them in. I also learned we need to charge a deep cycle with low amps. I think I killed one of my batteries by charging it too fast. 40 amp quick charge was a bad idea. Should have been less than half that. Many battery places will do a load test. In short I believe your batteries are gone. Hope I am wrong Best of luck