The most exciting part about the SOLO2 is the option to go Solo once again. No more worrying about running out of oxygen or waiting around for tank service. The SOLO2 gives you plenty of battery life to spend time with loved ones, enjoy an intimate dinner, attend a sporting event, or even just enjoy a day away from home. This easy loading battery slides into the back of the concentrator and is ready to go, featuring a very slender profile to make carrying extras easy and convenient. The easily accessible battery is located on the back of the machine where it is protected from shocks and moisture, unlike many concentrators that have batteries on the front where they can be susceptible to damage. The SOLO2 Battery can be charged in a variety of ways—both AC and DC chargers are included in the standard package, allowing you to charge with the unit itself without needing an external device. Battery life ranges from up to 4.5 hours on pulse setting 1 to 2.5 hours on pulse settings 3-5, and from 3.5 hours on continuous 1 to 1.5 hours on continuous 3. The battery weighs under 3 pounds and measures 6" W x 12" L x 1.5" H.