I have it on about a mile of fence. They don't touch it more than once. It works SO well that I have a hard time telling when there is something wrong with the fence. The readout is at 19.0 most of the time. Once it dropped down to 17 so I did a walk and found that a deer had taken down the whole back side of my fence. Probably 100 feet was laying on the ground and it was still snapping away. I try to get all the trees and stuff off of it, but if trees ARE touching it, it doesn't slow it down. They do honor their 1 year warranty. I took it in to the store I bought it from when it broke down. They sent it away and it was fixed for nothing. And apparently it had been hit by lightning!! That was a little close for comfort!
Ours is supposed to be indoors too, but we built a box around it with a Plexiglas front. The manufacturer said that is good enough coverage for it.
If one of the wires is not hooked up to the fence charger and you get a much stronger shock when both are touched versus touching just the hot one I believe it means that your fence charger is not properly grounded. If both are hooked up to the fence then it might be that you get a much better shock because it is getting power from both which is a no-brainer but probably means that your fence charger is not strong enough for the amount of wire you have hooked up to it OR that both wires are mildly grounded out somewhere along the way but when touched simultaneously give you the shock you should have gotten from touching just one because their power is combined.
I'm no electric fence guru so I might be wrong but I do know that the first explanation is true from personal experience (not well grounded).
These chargers are recommended for so many miles of fence. How many feet (or miles) of WIRE do you have...not fenceline but actual wire when you add up all strands together?
So if the fence is mildly grounded somewhere, would a stronger (not solar) charger solve that problem?