I've Been using one in DFW for a year. The life indicator on my battery turned from green to amber and then to being nothing, black. Then u decided to get this because the battery would drop to 12v after a drive. It's suppose to remain at 13.xV. It is an 09 pickup. I decided to try the Sunforce trickle charger from Cabelas. The square sized one. Haven't had a problem since. I notice the glass removes some UV but you won't see me mounting my solar charger in the exterior. It'll disappear. My 12v sockets are active whether ignition is on or off. I will continue using it. I use it on y four day trips. I do think it extends the life of batteries that are on their way out.