I have had a couple of the Schumacher 1.5 Maintainer for a few years now. However it seemed like one was not working as both the red and green lights were on. So I went to the local H of E and they were sold out. Two clicks on Amazon and two days later I had a couple. Went and replaced the one with a new one and seemed to be working correctly. However WTF the new one looked exactly the same but was extremely light. I didn't have a scale but I am sure the old one weighted 3 times more than the new one. Only hope the new one works as well and lasts as long as the old one. Some what weird!