According to Frontier Designs, TranzPort can be powered with a wide variety of AA-size batteries. It comes with four alkaline batteries, however you can use four non-rechargeable “zinc-carbon” batteries, which are less expensive, but only have about a third of the energy storage. You can also use four rechargeable AA-size NiMH or NiCAD batteries. (Note that when using fully charged rechargeable batteries, the BATTERY display may not show all ten asterisks since they charge to a slightly lower voltage than fresh alkaline batteries.)