Appendix C: Service and Maintenance89
All decimal points light in the display light when 2 to 5 minutes of operation time remain in the battery pack. Even when all the decimal points are lit, the true decimal position is known because an entire digit position is allocated to it.

Battery Pack Replacement

To replace your battery pack, use the following procedure:
1. Turn the power switch to OFF and disconnect the battery charges.
2. Slide the two battery-door latches toward the bottom 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.