Casio 2753 Stopwatch, Illumination, Battery, Battery Power Indicator and Recover Indicator, About the Auto Light Switch, Charging Precautions, Charging Guide

Stopwatch

Operation Guide 2753 3333

		Mode indicator				The stopwatch lets you measure elapsed time, split times,
						and two finishes.
						• The display range of the stopwatch is 99 minutes, 59.99
							seconds.
						• The stopwatch continues to run, restarting from zero
							after it reaches its limit, until you stop it.
						• Exiting the Stopwatch Mode while a split time is frozen
1/100 second Minutes							on the display clears the split time and returns to
		Seconds
							elapsed time measurement.
	Module 2753
						• The stopwatch measurement operation continues even
				Mode
							if you exit the Stopwatch Mode.
				indicator • All of the operations in this section are performed in the
							Stopwatch Mode, which you enter by pressing C.
		Minutes			Seconds
	Module 3333
To measure times with the stopwatch
Elapsed Time
D			➤D				➤D	➤D	➤B
Start				Stop			Re-start	Stop	Clear
Split Time
D			➤B				➤B	➤D	➤B
Start				Split			Split release	Stop	Clear
Two Finishes
D			➤B				➤D	➤B	➤B
Start				Split			Stop	Split release	Clear
				First runner			Second runner	Display time of
				finishes.			finishes.	second runner.

Display time of first runner.

Illumination

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. Make sure that the watch is normally exposed to bright light whenever possible.

•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 it 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.

Level	Battery Power				Function Status
Battery power indicator	Indicator
1					All functions enabled.
2					All functions enabled.
3	l	l ll			Alarm, hourly time signal,
				l	illumination, auto light switch,
	l			l
	l				and display are disabled.
	l		l	l
Recover indicator		l			Though the hands of the watch
					do not move, time continues to
	(Charge Soon Alert)				be kept internally.
4					All functions, including
					timekeeping, disabled.

• 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

Auto light switch indicator

The watch has 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 illuminates the face when you angle the watch towards your face.

•The auto light switch must be turned on (indicated by the auto light switch indicator) for it to operate.

•See “Illumination Precautions” for other important information.

To turn on illumination manually

In any mode, press Lto illuminate the display for about one second.

•The above operation turns on illumination regardless of the current auto light switch setting.

charged, but you need to set the time and date, after the battery reaches Level 3

(indicated by flashing charge indicator) from Level 4. You will not be able to set any

of the other settings until the battery reaches Level 2 (no charge indicator) 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 higher than

the actual battery level. The correct battery power indicator should appear after a

few minutes.

• If you use the light or alarms a number of times during a short period, the recover

indicator appears on the display and the following operations become disabled until

battery power recovers.

Illumination

Beeper tone

Coordination between digital and analog timekeeping

After some time, battery power will recover and the recover indicator will

disappear, indicating that the above functions are enabled again.

About the Auto Light Switch

Turning on the auto light switch causes the display illumination 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 illuminate the display 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 illumination to turn on.

•Wear the watch on the outside of your wrist.

Parallel to	More than
ground	40°

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 (the auto light switch indicator displayed) and off (the auto light switch indicator not displayed).

•The auto light switch 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.	Solar cell
• 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.

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 11 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)	6 minutes
Sunlight Through a Window (10,000 lux)	30 minutes
Daylight Through a Window on a Cloudy Day	48 minutes
(5,000 lux)
Indoor Fluorescent Lighting (500 lux)	8 hours

•Since these are the specs, we can include all the technical details.

•Display on 18 hours per day, sleep state 6 hours per day

•1 illumination operation (1.5 seconds) per day

•10 seconds of alarm operation 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	Approximate Exposure Time
(Brightness)
	Level 4		Level 3		Level 2		Level 1
		▲		▲		▲		▲
Outdoor Sunlight (50,000 lux)	2 hours				38 hours		11 hours
Sunlight Through a Window	8 hours				192 hours		53 hours
(10,000 lux)
Daylight Through a Window	13 hours				– – –
on a Cloudy Day (5,000 lux)
Indoor Fluorescent Lighting	157 hours				– – –
(500 lux)

•The above exposure time values are all for reference only. Actual required exposure

times depend on lighting conditions. 3