The impedance track gauge algorithm uses the information from both the voltage-based and coulomb-counting methods. When the load is very light, or the battery is idle, users can keep track of the voltage data which corresponds closely to the “OCV” condition. When load current is flowing however, users can use the coulomb counting method. Between these two pieces of information, given the right conditions one can estimate the battery’s internal impedance, and then also use that to estimate run-time remaining in hours and minutes based on the average current that is flowing. The battery temperature information is also used to compensate the estimates of capacity and run time remaining.