Extend mobility time - each Inogen One 12 Cell battery provides up to 4 hours of bastery operation. Lasting between 3-4 hours (depending on flow rate), the Inogen G2 Lithium Ion Battery is the perfect power source for trips to the store, seeing a movie or a dinner out with friends. Having an extra battery on hand is a great way to make sure that you can get up and go whenever you want.