Hey after 8 batteries in less than 8 hours of use, I was all set to buy the power-pack from ATN. When I saw it was a standard phone charger USB set up I tried one of those solar powered Patriot power cells I had bought for my phone when fishing. It works!!!! No more batteries or a hundred dollar power pack from ATN. I'm happy. Now if I can master this scope and all it's functions that easily.