Sometimes they do fail to reduce the charge level to a lower maintenance charge and will overcharge the battery. Mine did the in the Landmark. I replaced it with a different brand, supposedly a little more high tech, and no more problems. With the new converter and batteries I have used less water in 6 months than I was using in 2 weeks. Most have a 2 year warranty, but you have to send it back for a claim, hard to do if you are a FT though.