Microsoft has refuted allegations that Windows 7 is falsely reporting failing batteries - or even causing them to fail - saying that its operating system is simply pointing out an existing problem.
Users who apprently had fully operational laptop batteries before installing Windows 7 were complaining that, after installing the OS, the software was suggesting that they might like to get a new battery because the old one was knackered.
Microsoft is suggesting that its new power monitoring software is so clever that it is uncovering existing problems which just weren't apparent before.
"Windows 7 makes use of a feature of modern laptop batteries which have circuitry and firmware that can report to Windows the overall health of the battery," a Windows Engineering blog says. "This is reported in absolute terms as Watt-hours power capacity. 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 per cent degradation (when the battery is performing at 40 per cent of its original capacity) and in reading this Windows 7 reports the status to you."
The battery reporting routines were not included in previous versions of Windows so most users would be none the wiser as to the state of their portable power source.
But that still means anyone getting a "Consider replacing your battery" warning has at least 40 per cent of their battery's original power to hand. We have to wonder if Microsoft has started making replacement batteries in secret.
Microsoft insists that it has seen no reproduceable reports of incongruous notifications on new hardware and that in all the cases they have investigated, the report was caused by a degraded battery.
Perhaps the notification should read "your battery is operating at 40 per cent of its original capacity" rather than scaring unwitting users into forking out for a new battery they probably won't need for months with unnecessarily doom-laden warnings.