Summarize the following:
This will allow your battery to drain fully.   "   The battery light begins to blink when the battery pack has discharged to a low-battery condition. When the battery pack is fully discharged, the Power/Standby light turns off and the notebook shuts down.

Summary:
Disable Hibernation on your computer temporarily. Select the Power Meter icon on the taskbar, or select Start > Control Panel > Performance and Maintenance > Power Options > Power Schemes  Write down the three settings in the Plugged In column and the settings in the Running on Batteries column, so you can reset them after calibration. Select the drop-down lists and set all six options in both columns to "Never. Select the "OK" button. Disconnect the notebook from the external power source, but do not turn off the notebook. Run the notebook on battery power until the battery pack is fully discharged.