HP 12C Platinum User Manual page 265

Appendix F: Battery, Warranty, and Service Information
To install new batteries, use the following procedure:
1. With the calculator turned off, slide the battery cover off.
2. Remove the old battery.
3. Insert a new CR2032 lithium battery, making sure that the positive sign (+) is
facing outward.
4. Remove and insert the other battery as in steps 2 through 3. Make sure that
the positive sign (+) on each battery is facing outward.
5. Replace the battery cover.
Note: Be careful not to press any keys while the battery is out of the calculator. If
you do so, the contents of Continuous Memory may be lost and keyboard control
may be lost (that is, the calculator may not respond to keystrokes).
6. Press ; to turn on the power. If for any reason Continuous Memory has
been reset (that is, if its contents have been lost), the display will show Pr
Error. Pressing any key will clear this message.
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