The AC Power Adapter Model XPO130, standard with the XPO100B Invacare XPO2 Oxygen Concentrator, plugs into any standard household electric outlet any where in the world with power from 100 VAC to 240 VAC, and from 50-60 Hz. When the XPO2 is connected to household current via the AC Power Supply, it automatically charges the internal battery and attached supplemental battery, whether the XPO2 itself is operating at any flow rate – or turned off.