I bought this unit for my RV over 3 years ago and it has kept my battery strong and still works great. I really like that it can be placed on the case and it's exposed to the weather instead of being on the windshield. When I drive I leave it attached to the hood because the magnet is so strong I don't have to worry about it blowing off. Good product. I highly recommend it. I actually bought another one for my daughter's car as it's covered for a year while she's in Europe.