One of the great ironies of the mobile revolution is how we end up feeling even more dependent on cords, since we have to plug our devices frequently to recharge them. Battery recharging issues may have come to a head last year, when the first LTE devices shipped and users found they sometimes had to charge them twice (or more) a day, depending on usage. Now it’s on everyone’s mind, and surveys show that smartphone users consistently rank battery life as one of the top qualities they seek in a handset. But alas, physics is a tough task master, so there are only so many ways to improve battery life. You can make a device sip less energy, although this comes at the cost of reduced performance. The only major gains that hardware can provide tend to be major generational shifts in chips,...