Casio 3707 Operation Manual

MA0410-EA

Power Supply

The power supply of this watch uses a solar cell to generate electrical power, which is stored by a
rechargeable battery. Using or storing the watch where it is not regularly exposed to light, or allowing
it to be blocked from light by your sleeve for long periods as you are wearing it can cause the power
of the rechargeable battery to run down. To ensure stable operation, be sure to allow the watch to be
exposed to light as much as possible when you are wearing or storing it.

❚ Charging Precautions

Avoid charging the watch in the following locations, and anywhere else where the watch may become
very hot.
• On the dashboard of an automobile parked in the sun
• Very close to an incandescent light source or other sources of heat
• In a location exposed to direct sunlight for long periods
Depending on the light source you are using, the case of the watch may become quite
hot during charging. Take care to guard against burn injury after charging.
❚ Checking the Battery Level
Normal
Battery level
drops due to
insufficient
charging.
Jumps two seconds.
Normal Normal operation
Low Power Alert Time calibration signal reception disabled
Timekeeping Disabled Timekeeping disabled
• Even after the battery drops to the level that timekeeping becomes disabled, you will be able to
resume normal operation by charging the battery.
• After timekeeping becomes disabled, the hands will move to the current time after the battery is
recharged sufficiently.
• Keep the watch exposed to light until normal operation returns.

❚ To charge the battery

Point the solar cell (face) of the watch at a light source to
charge the battery.
• Remember that even a partial blockage of the solar cell
reduces charging efficiency.
❚ Charging Guide
Starting from a full charge, the watch should be able to
continue operating for about five months without further
charging under the conditions described below.
Daily Use (All time values are approximate.)
• Signal reception: 6 minutes
Making sure the watch is regularly exposed to light ensures
stable operation.
• Charge Times Required to Advance to a Higher Level
Exposure Level (Brightness)
Outdoor Sunlight (50,000 lux)
Sunlight Through a Window (10,000 lux)
Daylight Through a Window on an Overcast Day
(5,000 lux)
Indoor Fluorescent Lighting (500 lux)
• Note that the above charging times are for reference only. Actual charging time depends on a variety
of environmental factors.
Operation Guide 3707
Low Power Alert Timekeeping Disabled
Battery level
drops further due
to insufficient
charging.
Date indicator becomes Hands stop at
" " at midnight. 12 o'clock.
Required Daily Charging Time
• The following is the daily amount
of charging required each day to
support the operations under
"Daily Use".
Exposure Level
(Brightness)
Outdoor Sunlight
(50,000 lux)
Sunlight Through
a Window
(10,000 lux)
Daylight Through
a Window on an
Overcast Day
(5,000 lux)
Indoor
Fluorescent
Lighting
(500 lux)
Approximate Exposure Time
Timekeeping Restored
1 hour
3 hours
4 hours
37 hours

Power Saving

Power Saving puts the watch into a sleep state, which will cause the second hand to stop moving
whenever the watch is left in the dark.
• Note that hand movement may stop if the watch is blocked from light by your sleeve.
❚ How the sleep state works
The second hand stops whenever the watch is left in the dark for about 60 or 70 minutes between the
hours of 10:00 p.m. and 6:00 a.m. Time calibration reception continues to be performed at this time.
If the watch is left in the dark for an additional seven or eight days, the hour and minute hand also
stop. Time calibration is not performed while the hour and minute hands are not moving.
• Timekeeping continues internally even when the hands are stopped.

❚ To recover from the sleep state

Move the watch to a brightly lit location or press any button, and the hands will move to the current
time setting and resume timekeeping from there.
Approximate
Exposure
Time
6 minutes
30 minutes
48 minutes
8 hours
Full Charge
16 hours
78 hours
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