With your newly restored independence, you will want to take full advantage of the lifestyle enhancing benefits of the slightly used Inogen One G4. To fully maximize the portable use of your slightly used G4, the double battery should be your go to option. The double battery is rechargeable using an AC power supply, DC power cord, or an external battery charger, and is the recommended battery choice for active and traveling oxygen patients. Using the double battery, you will have the ability to run errands, travel, or catch up with friends or family for up to 4 hours and 30 minutes on a pulse setting of 2. Battery life ranges from up to 5 hours on setting 1 to 2.5 hours on setting 3. The control panel displays your remaining battery life in an enlarged battery gauge as well as in a percentage. Three charging options are available: the AC power supply charges through any conventional wall outlet, the DC power supply charges through any vehicle's battery, and the external battery charger allows you to charge an extra battery on the side. This double battery weighs 1.11 pounds.