Summary: Great glasses especially for the price. Yes they are not rechargeable, but the battery lasts a long time and they even include one with the glasses. I have had them for about a month and the battery still lasts.
Pros: Cheap, Works with Panasonic, Battery Lasts a long time, Lightweight, and I don't get a headache with these types of glasses
Cons: Flimsy but when you put them on they don't come off unless if you do somersaults or handstands
Summary: I have 2 pair of better glasses. I use these for when company wants to view 3D also my wife at times will use these as they work better over her perscription Glasses. I have read some reviews that are not satisfied that the glasses do not fold up.