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Operation Guide 2607 2637 2687
4
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.
• Note that charging efficiency drops
when any part of the solar cell is
blocked by clothing, etc.
• The illustration shows how to position
a watch with a resin band.
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.
Solar cell
• This watch employs a solar cell that converts light into electricity that 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. Should you notice problems with
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
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.
Module 2607 2637 2687
• The Level 3 charge warning indicator 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.
• 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 actually
higher than the 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 (R
/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 (R /
RECOVER
) will disappear, indicating that the above functions are enabled again.
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, while the
watch is used under the conditions described below.
Operating Conditions
•
Watch is not exposed to light
•
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
•
4 times calibration reception per day
Charge Times
Exposing the watch to light for the periods shown below each day restores the power
used by the above operating conditions.
• 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) 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
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.
Reference
This section contains more detailed and technical information about watch operation.
It also contains important precautions and notes about the various features and
functions of this watch.
Auto Return Features
• If you leave the watch in the Time Recorder Mode or Alarm Mode for two or three
minutes without performing any operation, it automatically returns to the
Timekeeping Mode.
• If you leave a screen with flashing digits on the display for two or three minutes
without performing any operation, the watch automatically saves anything you have
input up to that point and exits the setting screen.
Data and Setting Scrolling
The B and D buttons are used in various modes and setting screens to scroll
through data on the display. In most cases, holding down these buttons during a scroll
operation scrolls through the data at high speed.
Initial Screens
When you enter the Alarm or World Time Mode, the data you were viewing when you
last exited the mode appears first.
Time Calibration Signal Reception Precautions
• Reception is best when the antenna built into the 12 o'clock edge of the watch is
facing in the general direction of the signal transmitter. Note, however, that moving
the watch while the time calibration signal receive operation is taking place will make
stable reception impossible.
• Proper signal reception can be difficult or even impossible under the conditions listed
below.
• Radio interference can make signal reception impossible.
• Strong electrostatic charge can result in the wrong time being set.
• Even when the watch is within the reception range of the transmitter, signal
reception is impossible if the signal is blocked by mountains or other geological
formations between the watch and signal source.
Inside or
among
buildings
Inside a
vehicle
Near
household
appliances or
office
equipment
Near a
construction
site, airport, or
other sources
of electrical
noise
Near high-
tension
power lines
Among or
behind
mountains
• Signal reception is affected by weather, atmospheric conditions, and seasonal
changes.
• The time calibration signal is bounced off the ionosphere. Because of this, such
factors as changes in the reflectivity of the ionosphere, as well as movement of the
ionosphere to higher altitudes due to seasonal atmospheric changes or the time of
day may change the reception range of the signal and make reception temporarily
impossible.
• The watch is designed to automatically update the date and day of the week for the
period January 1, 2000 to December 31, 2099. Setting of the date by the time
calibration signal cannot be performed starting from January 1, 2100.
• This watch can receive signals that differentiate between leap years and non-leap
years.
• If you are in an area where proper time calibration signal reception is impossible, the
watch keeps time within ±15 seconds a month at normal temperature.