My solar charger is on the roof of the shed, I ran the wires into the shed. Pretty sure you could do the same thing.I bought a solar charger a lot like this a few years ago.
The idea was to place it on my Bronco dashboard to trickle charge the batteries.
For the bad assed stereo & lighting system I was going to magically install at some point really soon (at that time).
It's in a box somewhere. Never used it.
I don't get much sunlight in my garage, so it won't work too well for the motorcycle.