Does Button have a battery?Updated 2 months ago

No, Button has a wall plug and must be plugged in to operate. For reference, Button has a Type A (U.S.) 100-240V, UL Certified plug.  

If using Button internationally, Button’s power supply accepts worldwide voltage (100-240V and 50/60Hz). However, depending on the country you may need a plug adapter, but a power converter should not be needed anywhere.