If you are in reasonable driving distance from Groesbeck, I'll give you a brand new 6v solar charger. I bought two at Academy and only needed one. It's still in the package.
Whatever unit you wind up with, put the wiring in conduit, or the coons will destroy it. I didn't believe that the first time I mounted a solar charger....and the coons destroyed it completely. Amazing. I wish I had pictures.
I suppose I should also mention that the solar panel charger that I bought to replace the dead one was a bit more expensive and was metal where the first one had plastic. The freebie I have is mostly plastic, but it is free.