If the low battery symbol () appears on the display of the HP 35s calculator, replace the batteries as soon as possible. If the battery annunciator is on, and the display dims, data can be lost. If data is lost, the MEMORY CLEAR message is displayed.
Have the new batteries readily at hand before opening the battery compartment. Once the batteries are removed, replace them within 2 minutes to avoid losing stored information. Use only fresh batteries and do not use rechargeable batteries.
The HP 35s calculator takes two 3-volt CR2032 lithium coin batteries.
Follow these steps to install new batteries:
Turn off the calculator.
Remove the back cover of the battery compartment.
Remove the old batteries.
Insert the new batteries, each with the positive polarity facing outward.
Replace the back cover of the battery compartment.
warning:Do not mutilate, puncture, or dispose of batteries in fire. The batteries can burst or explode, releasing hazardous chemicals.