The DeVilbiss iGo AC power supply is for usage with any standard US wall outlet, which can also be used in many countries without a voltage converter. The AC power supply when plugged into the unit will power the iGo when there isn't a presence of a battery, though when a battery is attached the AC adapter will automatically begin to charge the battery, even when the concentrator is off. This is the perfect charging option for when you are catching up on your favorite TV shows—simply plug it into a wall outlet nearby and let the power supply do the rest. Recharging the DeVilbiss iGo battery is extremely quick with the AC power supply. A fully discharged battery will take approximately 2 – 4.5 hours to fully recharge, though operating the machine while charging will add to the charge cycle. If you plan on traveling internationally, a plug adapter may be needed in order to be used with varying types of wall outlets. This power supply operates on 100 – 240V, 50 – 60 Hz.