HP 82120A Rechargeable Battery Pack
Instruction Card
The HP 82120A Rechargeable Battery Pack may be used in the HP-41C in
place of the standard battery case and disposable batteries. Because the re-
charger connects directly to the battery pack, the pack may be recharged
while it is installed in or removed from the calculator. A fully-recharged pack
typically provides 6 to 12 hours of continuous program-running time for the
HP-41C with no plug-in peripherals or accessories.
Note: The nickel-cadmium cells inside the battery pack may be dis-
charged when you receive it. Connectit to the recharger for at least
a few minutes before installing it in the calculator. Then operate the
calculator with the recharger connected, as described below.
Installing the Battery Pack
To install the pack in the calculator, first turn off the calculator. Then remove
the battery case and replace it with the rechargeable pack. It fits just like the
standard case.
Recharging the Battery Pack
CAUTION
When the packis in the calculator, be sure to turn off the calculator
and any connected peripherals before connecting or removing the re-
charger. Be sure the recharger plug is fully inserted into the pack's
receptacle. If these instructions are not followed, the calculator or
battery pack may be damaged.
To recharge the battery pack while it is in the calculator, first turn off the calcu-
lator. Then remove the cover from the access hole in the side of the calculator
and plug the rechargerinto the battery pack receptacle, which shows through
the access hole.
Note: You can use the calculator while the battery pack is installed
and recharging.
To recharge the battery pack while it is removed from the calculator, plug the
rechargerdirectly into the pack's receptacle. After 12 to 16 hours the pack will
be fully charged.
Using the Battery Pack
The nickel-cadmium cells in the rechargeable pack operate much differently
from replaceable alkaline batteries. After the low battery indicatorturns on, the
rechargeable pack provides a reserve operating time of about a minute or
more—much less than with alkaline batteries. If you want to run a long, un-
attended program without using the recharger, you may want to include pro-
gram lines that check flag 49 (Low Battery) and execute OFF if the flag is set.
To preserve maximum capacity of your battery pack, charge it fully, then oper-
ate your calculator with the recharger disconnected. When the low battery indi-
cator turns on, connect the recharger again until the pack is fully charged. Leav-
ing the recharger connected at all times will not damage the pack, but will great-
ly limit its capacity.
When not being used, the cells in the rechargeable pack discharge at a rate of
about one percent of available charge per day. If it is not recharged, after 30
days the pack could have only 50 to 75 percent of its charge remaining.
Do notinstall and recharge a fully discharged pack in your calculator. Although
no damage will result, this action may disrupt the operation of the calculator's
circuits. The most common symptom is a loss of keyboard control of the calcu-
lator. To recover from such a condition, simply remove the battery pack and
install it (or another pack) immediately.
WARNING
Do not incinerate or disassemble the battery pack or short-circuitits
terminals. If you do, the pack may burst, release toxic materials, or
cause serious burns.
Observe the allowable temperature rangeslisted below. The temperatures for
the pack differ from those of the HP-41C calculator.
Recharging:
5° to 45°C (41° to 113°F)
Operating:
0° to 45°C (32° to 113°F)
Storage:
—40°to 50°C (—40° to 122°F)
Rechargers
Only the rechargers listed below should be used with the HP 82120A Re-
chargeable Battery Pack:
MODEL
AC VOLTAGE
IDENTIFICATION
HP 820598
90 to 120
United States
HP 82066B
210 to 250
Europe
HP 82067B
210 to 250
United Kingdom
HP 82067B Opt 001
210 to 250
Republic of South Africa
HP 82068B
210 to 250
Australia
HP 82069B
90 to 120
Europe