In at least one embodiment, a power management module measures different observable quantities of a battery, such as terminal voltage or current, and measures a voltage response of the battery based upon the measurements. The measured voltage response of the battery is compared to a plurality of reference voltage responses, which may be determined for authentic batteries, for example. If the measured voltage response corresponds to each of the reference voltage responses, the battery is authenticated for use with an electronic device. If necessary, additional voltage responses may be measured and compared against corresponding reference voltage responses until the battery is authenticated by a sufficient number of corresponding responses. A relative condition of the battery, such as an age or state of health, may also be estimated based on the measured voltage response of the battery.