There were at least two variations of this battery pack during it's production lifetime. This photograph shows the older 82001A on the right and newer 82001B on the left. The differences are very minor, in that the plastic of the 82001B appears to be slightly heavier and the metal contacts are exposed for a longer length than in the 82001A. Another difference noticeable in the photo is that in this particular set, the 82001A Ni-Cad cells are covered with a brown paper, while the 82001B Ni-Cad cells are covered with a plastic coating. I am not sure if this is true with all 82001B packs, however.
The 82001A/B packs were used in the following HP calculators: HP35, HP45, HP55, HP65, HP67, HP70, HP80, and HP75C/D. The HP75C/D expansion chassis used two 82001 packs.
There are at least two variations of the Spice battery pack. The pack is designed so that it can only be installed with the correct polarity, with a partial groove between the batteries, as seen in this picture. The battery pack on the right appears to be the older version, and contians a simple arrangement of spring steel and a plastic guide clip. The two Ni-Cad cells simply fit into the spring steel and the clip holds them in place - there is no solder or welding. It is quite easy to replace the Ni-Cads in the older version, simply remove the old cells and pop new ones (of the correct length - standard AA cells are a bit too long) in. The newer version, seen on the right, is plastic with a jumper strip connecting the two cells. The side of the battery pack that is seen when the pack is inserted into the calculator is shown in this picture, once again with the older variation on the right and the newer one on the left.
