Solio is a universal "hybrid" charger - one that can accept power from either the wall socket or the sun and store energy within its internal Lithium ion rechargeable battery. Solio uses this stored energy to power your mobile devices at the same voltage and current as if they were plugged into the wall. It can power all of your handheld electronic products indoors and outdoors. Because of its flexibility, Solio eliminates the need for you to purchase and carry around multiple chargers for all of your mobile devices. As far as efficiency goes, an hour under the sun will give it enough power to provide up to 25 minutes of additional talk time on most smartphones. When fully capacity, Solio can charge a smartphone at least twice.