Bud -- John and the rest of responders MY SINCEAR THANKS FOR YOUR HELP AND ADVISE --I got the new batteries in and all seems well so far, the Magnum inverter /charger sounds like it did when it was new and John I did call the people at Magnum (Dean) and they were very good at helping me out and confirmed that if a battery had a bad cell or worse that would cause the Magnum to do strange things. Will give a further update for others when it has been on for a couple of days. Cheers Blake at Lake Cowichan BC in the summer and Lake Havasu AZ in the winter