How old are they Mike? Reason I ask... tried them (gell cell) in a customers airplane at his request. He got 3 years out of the first one.. and 2 out of the second before we went back to typical wet cell. Same company's battery (Gill) but in a typical wet cell, same size, I got 9 years out of my first one in my airplane.. and to be safe (considering the back lakes I'm visiting) I just pulled mine again with 6 years on it and stuck it in a need worthy Lawn Tractor and installed a new one in the airplane.