Battery-powered devices which are capable of authenticating batteries. In one embodiment, a device comprises: a battery, an excitation source, a photodetector, and an operating system. The device is capable of at least partially being powered by the battery. The excitation source is capable of producing radiation and disposed so that the radiation can contact a surface of the battery. The photodetector is capable of detecting radiation from the battery. The operating system is capable of determining whether or not the battery is an authentic battery for that device.