Yes we did use an AGM battery. They make a 3 gallon gas tank that looks like an L from the side. When you tip the dinghy the gas flows into the L and uncovers, so to speak, the filler cap so the gas level is below the filler. And we secured them both so they wouldn’t move. The battery with a more permanent tie down, the gas tank with S/S rachet tie down. Amazon has the S/S rachet tie downs. I don’t think that we even closed the vent on the gas tank so it could expand and contract but it still didn’t leak.