The Solartab ($97 and available on Amazon) combines a 5.5-watt solar panel with a 13,000 mAh battery into an iPad-sized, neatly designed all-in-one package that’s robust, attractive, and well thought out. It can recharge both from a micro-USB port (at 2 amps) and via the solar panel (peaking around 1.5 A in full, cloudless sunlight), and provides power through two USB Type-A connectors at up to 2.1 A per port.
Its trouble isn’t any of the above; everything tested just as expected. Rather, it’s that it’s too expensive and too heavy for the job for which it’s designed. The Solartab seems designed for people who will be away from any source of plug-in electrical power—car charger or AC—for days at a time.