Although slightly off topic, I am reminded that National (Panasonic) used to make a range of batteries called "Hi-Top". I am not sure if they ever included an alkali cell and according to this history they used manganese. We were designing our own portable unit for the miltary powered by 6 D cells. I don't know where they got the dimensions for the batteries from, but when we tried to power it up for the first time we wanted high quality batteries and opted for the Hi-Top range. Big surprise- they wouldn't fit. We tried an Everyready D cells and sure enough they fitted fine. It then dawned on us why the product was named "Hi-Top". The top of the D cell was higher than any other. It probably fitted in a commercial product with more give in the spring contact, but it made suckers out of us.