Yes, lots of choices. I gave the protected Fenix battery to my son-in-law for his lantern as a spare and I just use unprotected 3400mAh green flat top Panasonic NCR18650B in it because I had a few of them. A 3500mAh NCR18650GA battery fits fine along with any protected batteries. Springs on both ends means the battery does not have to have a button top. Lots of choices. Since the built in charger charges up to 4.20v, I wouldn't use any of the 4.35v batteries.........but mostly what you will come across are likely to be the 4.20v Panasonic based cells.