Operation Guide 2869 2870
4
To change the Daylight Saving Time (summer time) setting
1. In the Timekeeping Mode, hold down A until the city code setting starts to flash,
which indicates the setting screen.
2. Press C twice and the DST setting screen appears.
3. Use D to cycle through the DST settings in the sequence shown below.
4. When the setting you want is selected, press A twice to exit the setting screen.
Auto DST (
AUtO
) DST on (
ON
)DST off (
OFF
)
Backlight
The backlight uses an EL (electro-luminescent) panel that
causes the entire display to glow for easy reading in the
dark. The watch’s auto light switch automatically turns on
the backlight when you angle the watch towards your face
in the dark.
• The auto light switch must be turned on (indicated by
the auto light switch on indicator) for it to operate.
• See “Backlight Precautions” for other important
information about using the backlight.
To turn on the backlight manually
In any mode, press L to illuminate the display for about
one second.
• The above operation turns on the backlight regardless of
the current auto light switch setting.
Auto light switch on indicator
About the Auto Light Switch
Turning on the auto light switch causes the backlight to turn on for about one second,
whenever you position your wrist as described below in any mode. Note that this
watch features a “Full Auto EL Light,” so the auto light switch operates only when
available light is below a certain level. It does not turn on the backlight under bright
light.
Moving the watch to a position that is parallel to the ground and then tilting it
towards you more than 40 degrees causes the backlight to turn on.
More than
40
°
Parallel to
ground
Warning!
• Always make sure you are in a safe place whenever you are reading the
display of the watch using the auto light switch. Be especially careful when
running or engaged in any other activity that can result in accident or injury.
Also take care that sudden illumination by the auto light switch does not
surprise or distract others around you.
• When you are wearing the watch, make sure that its auto light switch is turned
off before riding on a bicycle or operating a motorcycle or any other motor
vehicle. Sudden and unintended operation of the auto light switch can create a
distraction, which can result in a traffic accident and serious personal injury.
To turn the auto light switch on and off
In any mode, hold down L for about two seconds to toggle the auto light switch on
(auto light switch on indicator displayed) or off (auto light switch on indicator not
displayed).
• The auto light switch on indicator is on the display in all modes while the auto light
switch is turned on.
Battery
This watch is equipped with a solar cell and a rechargeable battery (secondary
battery) that is charged by the electrical power produced by the solar cell. The
illustration shown below shows how you should position the watch for charging.
Example: Orient the watch so its face
is pointing at a light source.
• The illustration shows how to position
a watch with a resin band.
• Note that charging efficiency drops
when any part of the solar cell is
blocked by clothing, etc.
• Normally, you should try to keep the
watch outside of your sleeve as much
as possible. Charging is significantly
reduced if the face is only partially
covered.
Solar cell
Important!
• Storing the watch for long periods in an area where there is no light or wearing it in
such a way that it is blocked from exposure to light can cause rechargeable battery
power to run down. Be sure that the watch is normally exposed to bright light
whenever possible.
• This watch employs a solar cell that converts light into electricity, which charges a
built-in rechargeable battery. Normally, the rechargeable battery should not need
replacement, but after very long use over a number of years, the rechargeable
battery may lose its ability to achieve a full charge. If you experience problems
getting the rechargeable battery to a full charge, contact your dealer or CASIO
distributor about having the rechargeable battery replaced.
• The rechargeable battery should be replaced with a CASIO-specified CTL1616
battery only. Other rechargeable batteries can cause damage to the watch.
• All data stored in memory is deleted, and the current time and all other settings
return to their initial factory defaults whenever battery power drops to Level 4 and
when you have the battery replaced.
• Turn on the watch’s Power Saving function and keep it in an area normally exposed
to bright light when storing it for long periods. This helps to keep the rechargeable
battery from going dead.
Battery Power Indicator and Recover Indicator
The battery power indicator on the display shows you the current status of the
rechargeable battery’s power.
Battery power
indicator
Recover
indicator
Level
1
2
3
4
Battery Power Indicator
(Charge Soon Alert)
Function Status
All functions enabled.
All functions enabled.
Beeper tone, backlight,
calibration signal
reception, display, and
buttons are disabled.
All functions, including
timekeeping, are
disabled.
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
• The flashing CHARGE indicator at Level 3 tells you that battery power is very low,
and that exposure to bright light for charging is required as soon as possible.
• At Level 4, all functions are disabled and settings return to their initial factory
defaults. Functions are enabled once again after the rechargeable battery is
charged, but you need to set the time and date after the battery reaches Level 3
from Level 4. You will not be able to configure any of the other settings until the
battery reaches Level 2 after dropping to Level 4.
•
Display indicators reappear as soon as the battery is charged from Level 4 to Level 3.
• Leaving the watch in direct sunlight or some other very strong light source can
cause the battery power indicator to temporarily show a reading that is higher than
the actual battery level. The correct battery power indicator should appear after a
few minutes.
• If you use the backlight or the alarms a number of times during a short period, the
recover indicator (RECOVER
) appears on the display and the following operations
become disabled until battery power recovers.
Backlight
Beeper tone
Calibration reception
After some time, battery power will recover and the recover indicator (RECOVER )
will disappear, indicating that the above functions are enabled again.
• If the recover indicator appears frequently, it probably means that remaining battery
power is low. Leave the watch in bright light to allow it to charge.
Charging Precautions
Certain charging conditions can cause the watch to become very hot. Avoid leaving
the watch in the areas described below whenever charging its rechargeable battery.
Also note that allowing the watch to become very hot can cause its liquid crystal
display to black out. The appearance of the LCD should become normal again when
the watch returns to a lower temperature.
Warning!
Leaving the watch in bright light to charge its rechargeable battery can cause it
to become quite hot. Take care when handling the watch to avoid burn injury.
The watch can become particularly hot when exposed to the following
conditions for long periods.
• On the dashboard of a car parked in direct sunlight
• Too close to an incandescent lamp
• Under direct sunlight
Charging Guide
After a full charge, timekeeping remains enabled for up to about six months.
• The following table shows the amount of time the watch needs to be exposed to light
each day in order to generate enough power for normal daily operations.
Exposure Level (Brightness) Approximate
Exposure Time
Outdoor Sunlight (50,000 lux) 5 minutes
Sunlight Through a Window (10,000 lux) 24 minutes
Daylight Through a Window on a Cloudy Day (5,000 lux) 48 minutes
Indoor Fluorescent Lighting (500 lux) 8 hours
• Since these are the specs, we can include all the technical details.
• Watch is not exposed to light
• Internal timekeeping
• Display on 18 hours per day, sleep state 6 hours per day
• 1 backlight operation (1.5 seconds) per day
• 10 seconds of alarm operation per day
• 5 times calibration reception per day
• Stable operation is promoted by frequent charging.
Recovery Times
The table below shows the amount exposure that is required to take the battery from
one level to the next.
Exposure Level
(Brightness)
Outdoor Sunlight
(50,000 lux)
Sunlight Through a
Window (10,000 lux)
Daylight Through a
Window on a Cloudy
Day (5,000 lux)
Indoor Fluorescent
Lighting (500 lux)
Approximate Exposure Time
Level 4 Level 3 Level 2 Level 1
1 hour 14 hours 3 hours
3 hours 70 hours 14 hours
5 hours 143 hours 28 hours
57 hours ------------ ------------
▲
▲
▲
• The above exposure time values are all for reference only. Actual required exposure
times depend on lighting conditions.