The OxyGo FIT External Battery Charger charges your FIT standard and double batteries while not connect to the portable oxygen concentrator. If you need to charge multiple batteries, then you should consider an external charger to speed up the process.
With an external charger, you can be charging one battery while charging a second battery in your POC. Extra batteries give you more power for the ultimate freedom and an external charger makes the process even more efficient.
*Battery NOT Included - (Charger Only)