When I get this Sony VGP-BPS2C Battery, there is an operating instruction attached to the notebook computer. As a new battery, I am really concerned about its quality and usage time. So I read the instruction carefully. It says to calibrate the Sony VGP-BPS2 VGP-BPS2A Battery once a month. Its the first time that I heard about the calibration of laptop battery.
Like this Toshiba PA3399U-2BRS Battery, its lithium battery which sport a level meter, like an electronic fuel gauge. Windows Mobile uses the information from those readings to display remaining battery level of the laptop battery.