Microsoft officials have dropped hints in the past that the company would be making a combined keyboard/cover for its Surface devices that would include a built-in battery.

The latest anonymously sourced reports from Neowin.net and the Windows SuperSite indicate these new covers are, indeed, in the pipeline.

The so-called Power Covers will extend the battery life of the Intel-Haswell-based Surface 2 Pro, existing Intel-based Surface Pro and the coming ARM-based Surface 2, those sources are saying, but there's no word on exactly how much extra life they will add.

According to Windows SuperSite's Paul Thurrott, the new battery-inclusive Type Power Cover will be .38 inches (9.75 mm) thick, compared to .21 inches (5.33 mm) for today's Type Cover.

The new covers may not be available until some time after the actual launch of the new Surfaces, however, the reports indicate.

Microsoft's first-generation ARM-based Surface RT devices sported eight- to ten-hour battery life. (My actual experience -- after Microsoft replaced my original Surface RT due to my suspicious battery report -- has been it's closer to seven, but that's still pretty decent.) The first-generation Intel core i5 Surface Pro devices only clocked in at four to five hours of battery life , which was fine for some users and problematic for others.

Microsoft officials also have hinted that the company will be making the Surface keyboards -- both the Touch and Type ones -- available in more colors at some point. At the company's partner show, Microsoft officials reiterated that Surface peripherals would be coming in additional colors .

There's no word in either report from today, September 5, as to how much additional Microsoft will be charging for the Power Covers. Microsoft recently made permanent a $40 cut to the price of its Touch covers for Surface , resulting in them starting at $79 (U.S.)

In case it's not clear, Microsoft officials are not commenting on the next-generation Surfaces or Surface peripherals.