Since you went with the ARYA Mini portable oxygen concentrators, you have the ability to choose from 3 different sizes of battery options. The ARYA Mini gives you the option to pick between a single, double, or triple battery. If you want the lightest overall package, the single battery is the best option. If you prefer the balance of both weight and battery life, the double battery is the top choice. If you want the longest operation away from a power source in exchange for a slightly heavier package, the triple battery is what you’re looking for.