Report Deep cycle battery found empty... in Tech Talk Posted yesterday at 04:42 AM Its stuffed. "Sealed" batteries are not sealed, they are valve regulated, and can still off gas if overcharged. You need a proper 3 stage regulator for your solar panel. If it was at float voltage it would have taken years for the battery to get low on electrolyte, let alone dry. So, if you have a regulator for the solar, its not working properly, or not programmed properly. If you dont, you need one.