Here is another backpack you can take anywhere to keep your smartphones and other USB devices charged. The Voltaic OffGrid Solar Backpack has monocrystalline solar cells to charge most smartphones in 3.5 hours. It has a compartment for laptops up to 15″. It can also hold tablets up to 10.
The Voltaic OffGrid Solar Backpack can charge camera batteries, tablets, GoPro action cams, and all kinds of other USB devices. The included battery has 12,000m Ah capacity and dual USB ports.