I would never have thought of it because I've seen many, many different styles of endcaps at the positive ends of 'AA' batteries alone.
The way this would have to work, given the use of 'no additional components', would be by tying the center contacts together at both ends of each cell, and doing the same with the outer contacts. So if a cell's positive endcap isn't perfectly flat, it would be likely to make contact with both terminals at that end, which would short out the whole cell.
IMO, Microsoft's patent attorneys are only the first of many attorneys you'll be paying if you implement this scheme in a mass-marketable consumer device.
The way this would have to work, given the use of 'no additional components', would be by tying the center contacts together at both ends of each cell, and doing the same with the outer contacts. So if a cell's positive endcap isn't perfectly flat, it would be likely to make contact with both terminals at that end, which would short out the whole cell.
IMO, Microsoft's patent attorneys are only the first of many attorneys you'll be paying if you implement this scheme in a mass-marketable consumer device.