HP calculator battery packs
All LED calculators and the HP-41 series are supplied by rechargeable battery packs. Each series uses its own type of battery pack. To charge the battery pack a dedicated charger must be used.
Classic Series battery pack HP 82001A and HP 82001B
The models of the Classic series are supplied by a battery pack that is build from 3 AA size NiCd cells. The batteries are connected in series which results in a nominal supply voltage of 3.6 Volt.
 |
 |
|---|---|
 |
(The red caution sticker was glued on the backside of an HP-35 battery door)
So far I found two types of battery packages for the Classic series. The battery packs look almost identical. The only difference that I observed was the size of the slots for the battery contacts. For the HP 82001B pack these slots are wider.
 |
 |
| HP 82001A | HP 82001B |
|---|
The batteries are charged in the calculator by a dedicated Classic series
charger.
To charge the Classic battery pack outside the calculator, HP sold a Reserve Power Pack, the HP82004A.
Woodstock Series battery
pack HP 82019A and HP 82019B
The battery pack for the Woodstock models has been build into the door of the battery compartment.
 |
 |
The HP 82019B with the original rechargeable
|
A rebuild battery pack.
|
 |
The battery compartment of a Woodstock model. Hovering over the picture will show the battery polarity. |
 |
What is the difference between the HP 82019A and HP 82019B? The beveled corners of the A model are slightly larger compared to the B model. So, the B model can hold batteries with a slightly larger radius. |
The calculators from the Woodstock series are supplied by two AA type NiCd cells. These cells are connected in series, which results in a nominal supply voltage of 2.4 Volt.
The batteries are charged in the calculator by the Woodstock specific main charger. The charger electronics is build into the calculator and not in the wall plug charger.
 |
 |
| Often you will find battery doors with the plastic strip removed. In this way this battery door can hold two standard AA size (rechargeable) batteries. | Additional batteries were sold in a paper sales package. |
To charge the HP 82019A/B battery pack outside the calculator, HP sold a Reserve Power Pack, the HP 82028A.
Topcat Series Battery pack HP 82033A
The battery pack for the Topcat series contains four sub-C size rechargeable batteries.
 |
 |
 |
|
| Warning sticker glued on the HP 82033A battery pack |
 |
 |
| The pictures above show a rebuild HP 82033A battery pack. The original pack was opened with a knife and the original (dead) cells were replaced by 4 modern capless NiMH 3300 mAh sub-C type cells with solder tabs. | |
This HP 82033A battery pack is also used in the HP 82143A thermal printer.
To charge the Topcat battery pack outside the calculator, HP sold a Reserve Power Pack, the HP82037A.
Sting Series battery pack HP 82052A
Both models of the Sting series are supplied by a battery pack containing four AA size rechargeable batteries.
 |
 |
| A four battery pack of a Sting series calculator. | The contact openings towards the batteries are positioned on the site of the pack. |
Spice Series battery pack HP 82109A
The calculators of the Spice series are supplied from a battery pack of 2 AA size NiCd batteries. The batteries are connected in series to deliver a total supply voltage of about 2.4 Volt. The batteries are hold together by a metal clip. This metal clip also connects both batteries in series. The batteries are charged in the calculator when supplied from the wall plug charger.
 |
 |
|---|
The dimensions of the rechargeable cells used in the Spice series calculator are: diameter 14.2 mm, length 48.8 mm. Modern high capacity rechargeable AA cells are a bit larger. Insertion of these modern cells will bend or can even break-off the battery contacts. Broken battery contacts due to insertion of too large cells or corrosion caused by battery leakage is often observed for this series of calculators.
To charge the Spice series battery pack outside the calculator HP sold an external charger, the HP 82103A Reserve Power Pack.
HP41 Series batteries HP 82120A
 |
The HP 82120A rechargeable battery pack contains 4 battery cells and the electronics to charge these batteries. More information about this module can be found here. |
 |
The HP-41 series
calculators can also be supplied by four standard N-type batteries. They
are placed in a separate battery holder. The N batteries have the same diameter but half the length of an more standard AAA battery. A rechargeable version of this batterie is also available and can also be placed in this battery holder. These cells can NOT be charged inside the HP-41. Only the HP82120A pack can be charged inside the HP-41 series by the mains charger. |
Links related to HP calculator battery packs
- HP museum
- Making New Battery Packs for the HP-35 Calculator by Douglas W. Jones.
- HP Calculator Battery Pack Rebuild by Chris Codella, W2PA
- Forum discussion about renew battery pack HP-97
- Using 4/5 AA cells as power source for spice calculators with broken battery clips by Sadsilence
- HP Spice battery connector by Panamatic (Bernhard Emese).
- HP 82033A battery pack refurbishment by Uli Schwalvenberg