Here is another backpack that lets you conveniently carry your laptop and smartphone and keep your gadgets charged. The HANERGY 8W Solar Messenger Bag comes with 2 USB ports to charge your USB devices. It has MiaSole solar cells with high solar efficiency. The bag has multiple compartments for separate storage of your laptop, tablet, pens, keys, and books.
This backpack is lightweight and waterproof. Its USB ports have an output of 5V 1.2A. 4 color options are available. You can get this bag for $70.