BatteryMon

Batteries, given their chemical nature, are prone to wear, corrosion, leakage and outright failure due to events like short circuits and lightning strikes. Given their propensity to fail and to have decreased performance over time, it is important to be able to identify and monitor their performance. With BatteryMon, monitoring the state of your battery has never been easier.
BatteryMon is an easy to use Windows program that allows the monitoring of laptop computer batteries and uninterruptible power supplies (UPS). Graphically see the battery charge / discharge rate, diagnose problem battery cells, compare your batteries performance with expected discharge rates and see the status of each individual battery pack (when multiple batteries are in use). Batteries and BIOS must comply with the Windows, Advanced Configuration and Power Interface (ACPI) specification in order for BatteryMon to work correctly. More than 20 statistics are provided including voltage levels, battery chemistry, full capacity level, current capacity, bias settings, device names and serial numbers. A log file is maintained of the battery charge level and other statistics for later analysis and the software comes with a comprehensive help file.