Anker's 2nd gen Astro E4 is fantastic as a short road trip battery. I love its size and shape for packing on a motorcycle.
The Astro E4 comes with 2 auto-sensing USB ports. If you have a device that'll charge faster, Astro feeds it more power. The 13000 mAh capacity is pretty much perfect for keeping my iPhone 5, iPad Mini and Go Pros going over the course of a 3-4 day trip. The battery does get quite warm when it has two charging ports going at once. Also to note, the unit has a total out put of 3A, so charging 2 iPads, or the like, at once will not be quick.
The only moving part is a status button. The Astro E4 is shaped like a pencil case and weighs about one pound. It is slightly less than 6 inches long, 2.5 inches wide and less than 1 deep. The unit fits in a breast pocket of my jacket but I prefer to keep it in a backpack or saddle bag, as its a little too large to be hanging off my person.
The Anker Astro E4 is bigger than I want to carry when flying but is perfect for road trips and camping. I'm very happy with it.
Previously on Boing Boing: