Though we won’t go into crazy levels of detail, the battery used in Gum Pro and Gum Plus is a serious piece of hardware: most of the batteries we have seen for the iPod and iPhone over the past year are capable of doing a single recharge of an iPhone model, with correspondingly more recharges—say, 1.5, 2, or 3—for a less power-hungry iPod, depending on the model. Other companies typically charge $60 or $70 for these batteries, sometimes…
