A:Answer although the other two answers are "politically correct"... and maybe best for the warranty police...LOL.... BUT the battery IS replaceable for a DIY type person. It is a simple 18650 battery. The flashlight opens from the very end of the tail and in the center behind the filament. The battery has a wire running along its length and is taped on both the positive and negative ends, this connects to the positive and negative wires from the switch. This wire could be un-taped from the old battery and re-taped to the new battery. To do this, it is best to open the light from behind the filament, NOT the tail. In this configuration, the battery needs to be recharged from the Micro USB as intended.
* I actually own this flashlight and have taken it apart and checked the battery for myself.