I now that there is no excuse on this, but I have lost battery cap of my Nikon F2. Which is the one to replace it with? I have seen tall ones and short ones, yet I don't remember which one is of the proper size.
Not sure I know what you mean by "tall" and "short" -- there is only one size battery cap. I don't know the size offhand, but it might be interchangeable with the battery cap from the Nikkormats, since those are also bayonet style (1/4 turn opens it).
if you mean the black plastic winglets that hold the battery/batteries in place, all my F2 bodies have the short cap, i.e. just the bayonet lid, no winglets. i see the tall screw-in ones in my FM2s