MacBook Air owners. The EP-15V from Bird Electron will bridge eight of those C batts to create a 12-volt power source, giving your 11.6-inch MacBook Air a two-hour boost when used with standard alkaline batteries. The charger was released today in Japan, and will initially sell for ¥19,800 (about $250), not including batteries or the requisite MagSafe Airline Adapter (¥5,800, or about $75 in Japan). The EP-15V isn't likely to be the most practical option, considering its cost, size, weight (2.3 pounds, or just over 1 kilogram -- before you add batts), and the fact that you'll need access to an adapter and eight batteries, which you'll be tossing after just two hours of use. But if you find yourself in a remote village with a hearty C-type battery supply and no electricity or access to the sun, then you might just regret not picking one up.