Transcend Portable Solar Battery ChargerDescription The Transcend Portable solar panel battery charger folds out and makes charging very easy. You can use your CPAP machine anywhere if it is being charged by this device. You can simply charge the batteries during the day, and be ready to use them at night. There are certain areas that are prone to frequent power outages, and now you no longer have to endure them interfering with your CPAP therapy. You can choose to use it with the P4