Here is the latest road find. The drop chipped the glass and that is a very complex piece of glass. The battery is 21 by 80 so it looks like they took a 21700 and added a charging port. The negative side has 2 electrodes so if you do manage to get a 21700 in there it will either short the battery or burn up the secondary charging port. I don’t like the dual or triple electrodes batteries and this one is worse because there is 5mm of slop for the battery to move around. I removed the dual electrode and flat electrode from my Craftsman. The writing is in several fonts it reads EL3603_B KZ-1 E337072 94V-O backwards RU 2031 and a Z with two extra marks. This left a standard 18650 battery. Both ends unscrew but I could not find a way to get at the glass which has a surprising amount of dirt. Slide focus lights are impossible to seal. On some lights you can fix the focus and seal with electrical tape. This is impossible with this light. The extra charging port can be accessed by unscrewing the tail and inserting a USB C cable. The charging port both screws and the slide were full of ground sand which sets my teeth on edge when I use them. Don’t buy you are better off with an as seen on TV light and yes they come with bigger batteries now.