They used to say a dog was a man’s best friend—but not any longer: For many people, the best friend is a cellphone. Cellphones don’t eat, they don’t need walking, they don’t need to see the vet, and they don’t wake you at midnight barking at something on the stairs that only they can see. (Got ghosts?) But one thing a loyal cellphone, or its cousin, the tablet, demands is electricity: Its minuscule battery needs frequent feeding with low-voltage juice at least every night for most folks, and more often for some. That means a snaky USB cord, plugged into a computer or a power adapter that is itself plugged into a 120-volt outlet. Frequent plugging and unplugging eventually damages the cord, and sometimes the phone’s port, too, and dealing with the paraphernalia takes away some of the convenience of carrying a supercomputer in your pocket.
The answer? Lose the wires and the adapter and
