Honeywell MN10CES Owner's Manual page 13

Battery Installation: Remove the cover on the back of the remote control and insert two AAA
batteries with ''+'' and ''-'' pointing in the proper direction according to the polarity markings.
Caution
• Use only two AAA or IEC R03 1.5V batteries.
• Remove the batteries if the remote control is not in use for a month or longer.
• All batteries should be replaced at the same time, do not mix with old batteries.
• Properly dispose of used batteries.
USE & OPERATION
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