My military grade nightvision actually use normal AA-batteries, and they also last very long with one single battery. Anyways, I like your post, because I mostly play Dayz on night and this is one of my biggest concerns. Give one man a NV, and he is able to kill every other playing without easly. With locked screen-settings, every player will end up wandering around in pitch-dark many places and completely unable to see the NV-guy. Forcing people to use chemlights, flares and flashlight at night is how I really want this game to end up. My thought is that they should make Nightvision very rare, and make some kind of special military battery for it. Normal batteries should not be rare, since the flashlight, rangefinders etc also will need it. tl;dr: Nightvisions should be very rare, and have its own sort of rare military batteries.