The Oxlife Independence DC Power Supply gives you the freedom of charging your batteries and powering your concentrator while you are on the go without the bulky and awkward power box. This feature makes it easier to bring the DC power supply with you whenever you are out and about. With the Oxlife Independence DC Power Supply, you will never have to worry about running out of battery life while you are in the car. Whether you are in-between errands or on a road trip, this power supply has the ability to power your concentrator and supply you with oxygen on every flow rate. On pulse flow settings 1-4 and continuous flow settings 0.5-2.0 LPM, the DC power supply has the capability of charging one or two batteries that are inserted in the concentrator. If you require a flow rate higher than 4 pulse or 2.0 continuous, the concentrator will draw too much power to recharge your batteries. However, your Oxlife Independence will still run off of DC power to conserve your remaining battery life.