Appendix D: Operating Characteristics
Temporary degradation, peculiar to nickel-cadmium batteries, may cause a decrease in the operating period of the battery pack. Should this happen turn the HP-80 on for at least five hours to discharge the batteries completely. Then put it on charge for at least 14 hours. This should correct the temporary degradation.
If the battery pack won’t hold a charge, it may be defective. If the warranty is in effect, return the pack to Hewlett-Packard according to the instructions on page 74. If the battery pack is out of warranty, use the Accessory Order Card provided with your HP-80, to order a new battery pack. Remember, you can use your HP-80 ac power until the replacement battery pack arrives.
Battery Pack Replacement
1. Turn the power switch to OFF and disconnect the battery charges.
2. Slide the two battery-door latches (the top feet) toward middle of the calculator.
3. Let the battery door and battery pack fall into the palm of hand.
4. See if the battery connector springs have been inadvertently flattened inward. If so, bend them out and try the battery again.