Truly enjoy the freedom and independence provided by your Zen-O portable oxygen concentrator and give yourself more time to do the things you love with the Zen-O 12-Cell Battery. Weighing in at 1.45 pounds, the 12-cell battery gives you hours of extra freedom without weighing you down. Unlike other continuous flow units on the market, the Zen-O 12-cell battery is small and compact making it easy to store for future use. One of the best features the Zen-O portable oxygen concentrator has to offer is that it can operate using one or two batteries. By using one battery you keep your concentrator at a true 10 pounds, and when using two batteries you double your battery life while adding less than 2 pounds to the total weight. Battery life ranges from up to 4 hours on pulse settings 1-2 to 0.75 hours on continuous 2.0 LPM with one battery, and doubles with two batteries. The Zen-O has the best battery life in its class, allowing you to road trip across the country or spend a full day at the beach without worry. For charging, you have multiple options including the AC power supply for home use and the DC power supply for charging in your vehicle through the cigarette lighter outlet. If you have multiple batteries, consider the optional external battery charger which typically charges batteries faster since they aren't in your concentrator.