BatteryMon is a battery and uninterrimpuble power supply monitoring tool. It displays quite a lot of useful information about how your laptop battery or UPS solution is currently working and it allows you to compare it to how the devices were working in the past.
The application allows you to test your battery and analyze how it charges and discharges, which gives you enough information to troubleshoot your battery and any potential problems you might have or will have in the future. Ideally, you would run this application with a full battery and disconnect the A/C power to let the program see how the battery discharges. By doing this, you might notice that the battery is not retaining the power that it should or that it is draining too fast. BatteryMon shows a graph that displays the battery discharge rate over time. Additionally, you can also get information about the battery and your system.
BatteryMon isn't a free tool, but you can use it for a whole month before it asks you to enter a serial number.