I have for sale a Gill G-242 24 volt battery, filled with acid, charged, used once. (long enough to realize the starter didn't turn over). After I replaced the starter, I verified that it is a good battery as the engine fired right up. I decided that since my previous battery is only a year old, I'd put it back in and sell the new one. I'd keep it if it didn't have a shelf life and obviously I cannot return it. So my loss is your gain. I paid $700 for it. (I know there are places that sell it for less, but I needed it right away and all the popular places were on backorder). So, for anyone who needs a battery for their Lycoming O-235-L2C or similar. I have the deal for you!