Extra battery for VP-2

Please note: the accessories may be shipped separately from the oxygen concentrator, which will take 10-15 working days to deliver.The oxygen concentrators are usually shipped in 2-3 days after placing the order, and in about 3-5 working days, they will arrive. Before purchasing: Return & Refund services are not available for this accessory product. Please read the description carefully or contact our Customers Service Team for more information. Specifications: Rechargeable Lithium-Ion Battery for VP-2 Model One Single Battery Duration: Up to 3.5 hours   Volume： 6400 mAh One Double Battery Duration: Up to 6 hours    Volume：10400 mAh The single/double Battery is a rechargeable Lithium-Ion battery for the VP-2 model. It provides portability for your active lifestyle. When you're away from a power source, this battery will keep your concentrator running so that you can stay active longer. A single battery will give you up to 3.5 hours of battery life, or a double battery to pr