These glasses are great, because a pair of personal glasses do fit in them, so that both people with glasses and no glasses can watch with them. They use battery, but don't be concerned, a battery is included, and you can watch up to 90 hours, until you have to change the battery. The battery is one of these flat ones, you can by a bunch of them for a low price: http://www.amazon.co.uk/Panasonic-Specialist-Lithium-Batteries-CR2025/dp/B002EVOA4K/ref=pd_bxgy_ce_img_b
The only thing that I do not like is the price of these 3D glasses. It is way to expensive and yet there aren't so many movies to watch in 3D.