I work out of a backpack six months out of the year. Since power outlets aren't always accessible, I rely on power banks to keep my gear in working order.
Power banks weigh in on the hefty side. For all their added bulk, they have never delivered enough oomph to keep my devices going when I'm traveling. And wall chargers are iffy too. Most I've tested are built for one device only, which means I have to load my pack with numerous cables and chargers. Not fun! Those chargers that do have more than one port are weighty, missing a foldable plug, or take up too much real estate.
Full story from the WindowsCentral blog...