Walgreens WGNBPW-710 El Manual página 13

Replace the batteries if:
switched on.
As the supplied batteries are for test only, they may
be discharged earlier than batteries you buy in stores.
Replace all batteries at one time (as simultaneous set).
time. Date and time will need to be reset if batteries are
removed or replaced. Clean contacts on battery and in
battery compartment with a soft dry cloth each time you
install batteries.
Note:
together with the household garbage.
12