Windows 7 makes use of built-in features of batteries that allow the battery health status to be read. "This is reported in absolute terms as Watt-hours (W-hr) power capacity," Sinofsky explains, "Windows 7 then does a simple calculation to determine a percentage of degradation from the original design capacity. In Windows 7 we set a threshold of 60% degradation and in reading this Windows 7 reports the status to you."Source: OS News
The key point here is this: this functionality was not part of Windows XP or Windows Vista. As such, people who think Windows 7 is causing the batteries to fail have it backwards; the battery was already in need of replacement, but XP nor Vista had the ability to report that to you.
Microsoft explains there's no battery bug in Windows 7
Posted on Tuesday, February 09 2010 @ 20:22 CET by Thomas De Maesschalck