Understanding the interaction between performance and power consumption in mobile systems to accurately predict battery life

When designing and using a wearable system, it is important to find the appropriate trade-off between system performance and battery life. Methods currently used for evaluating battery life over a range of CPU clock frequencies are often inaccurate because they fail to account for the fact that overall system performance usually does not scale proportionally to CPU clock frequency. We present a modified method that works in all cases, and characterize the battery life of the test system over a range of frequencies.