The problem with NVG and all the battery operated stuff is that once it runs out its useless unless you have a means to recharge it through an offgrid power system and the electrical knowledge to make sure you dont cook them in case of a jerry rigged system. It might be really useful for a good couple hours of operation but after that it becomes useless junk you spend calories or fuel hauling around with the faint hope of maybe being able to recharge it again sometime in the future