I purchased a Firefly version 1 it never worked right, so just put it away. Years later was going to throw it away, then i went online and chatted with a rep. He advised a new battery, so I ordered a new battery. Works like a charm now, the original battery was no good. Like the new tab on the battery for easy removal.

This battery works. It powers my Firefly classic original vaporizer, 6 years old. Even though the old batteries still work, which is amazing, this one is better. Maybe because it is new. It seems to last longer between charges, and easily brings the vaporizer temperature way up. It is a good battery.