The Inogen One G3 External Battery Charger with Power Supply is designed to charge the Inogen One G3 battery cell when removed from the oxygen unit.
Have a secondary battery that needs a charge or charging your battery away from the device? The external charger connects to the battery and the included AC cord. Plug the charger into an AC power outlet to begin charging the battery. If fully depleted, it may take up to 4 hours to charge a 8 cell battery and up to 8 hours to charge a 16 cell battery.