My dad has an solar power system he brought on my elk hunt this year. It consists of two 48w folding panels with stands, a charge controller, and a lithium battery pack. He laid out several cables and we had unlimited use of LED tent & cooking lights, universal battery chargers for AAA AA C D & 9v batteries, we charged cell phones, video cameras, GPS batteries, and we even got to use a laptop for the entire trip. We were spoiled rotten.
I have a couple of those small 12v 6w folding panels from Brunton that I daisy chain together to power my battery charger so I can keep all my battery opperated items going.
You can use suction cups to stick them to your windshield facing the sun to charge your spare batteries while you're out hunting, or to keep your truck battery charged up, too.
I bought two of the 6w panels because they're cheaper than one 12w panel, and I need at least 10w to power my charger.
Welcome to the 21st century. Aint it great?