Sharp Mobilon HC-4000 Operation Manual page 24

2. Slide the battery replacement switch to the REPLACE MAIN BATTERIES
position.
3. Pull out the battery holder and remove the old batteries. Discard them
properly.
4. Insert two new AA (LR6) alkaline batteries into the battery holder, noting the
directions indicated by the plus (+) and minus (-) signs inside the holder.
Caution:
If you need to place the main battery holder containing batteries on a table
made of metal, make sure the batteries are not in direct contact with the table;
otherwise a short circuit may occur, and the batteries may heat up and
explode.
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