Citizen Corso BM8400-50A User manual

CONTENTS
A. BEFORE USING..........................................................................................2
B. SETTING THE TIME AND CALENDAR......................................................3
C. FUNCTIONS OF SOLAR POWERED WATCH ..........................................6
Insufficient Charge Warning Function..........................................................7
Quick Start Function ....................................................................................7
Overcharge Prevention Function .................................................................7
D. CARE AND HANDLING DURING CHARGING ..........................................8
E. ABOUT THE RECHARGEABLE CELL ......................................................9
F. TIME REQUIRED FOR CHARGING .........................................................10
G. IN THESE CASES .....................................................................................12
H. PRECAUTIONS.........................................................................................14
I. SPECIFICATIONS.....................................................................................20
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English

A. BEFORE USING
This watch is not powered by a conventional battery, but is powered by
converting light to electrical energy.
Once fully charged, the watch will continue to run for approximately 6 months
without additional charging. We do recommend exposing your watch to light
every day to ensure optimum performance. Always be sure to recharge the
watch before it stops.
Your watch features an Overcharge Prevention Function so there is no need to
worry about overcharging your watch.
A special energy storage cell is used to store electrical energy. This special cell
does not require replacement and is a clean energy unit that does not use any
toxic substances.
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Before using, be sure to fully charge your watch by exposing it to light.
(See “F. TIME REQUIRED FOR CHARGING”, for charge time reference)

B. SETTING THE TIME AND CALENDAR
Setting the time
1. Stop the second hand by pulling out the crown.
2. Turn the crown to set the time.
3. After setting the time, firmly push the crown back into its normal position.
3
Time-setting position
Crown
Solar cell
Normal position
[1] Three-hand models without calendar display
* If your watch has a screw-type crown, lift up the crown to loosen it before
operation. Be sure to press the crown down firmly after operation.

7
7
SUN
4
Time
setting
position
Time
setting
position
Calendar setting
position
Crown
Date
Solar cell
Normal position
[2] Models with calendar (date and weekday) display
* If your watch has a screw-type crown, lift up the crown to loosen it before
operation. Be sure to press the crown down firmly after operation.
[Date display models] [Date, day of the week
display models]
Solar cell
Crown
Date, day of the week
Normal position
Calendar setting
position
The position of the calendar may differ depending on models.

Setting the time
1. Stop the second hand by pulling the crown out to the 2nd click (time setting
position).
2. Turn the crown to set the time.
3. The watch will start after the crown is firmly pushed back into its normal
position.
Setting the calendar
1. Pull the crown out to the 1st click (calendar setting position).
2. Set the desired date by turning the crown counterclockwise.
3. Set the desired day of the week by turning the crown clockwise.
•In the case of date display models, turning the crown clockwise will result in
the loose play of the crown.
4. After you have set the calendar, be sure to press the crown back to its
normal position.
•Do not adjust the calendar when the watch is reading as below. Otherwise
the calendar may not change correctly.
* Date display models ..... between 9:00 pm and 1:00 am
* Date, day of the week display models ..... between 9:00 pm and 4:00 am
5

C. FUNCTIONS OF SOLAR POWERED WATCH
If the charge becomes insufficient, a warning function will operate and the
display changes, as below.
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Normal time
display
Stop
Insufficient charge
warning display
One second
interval movement Two second
interval movement
If charged
sufficiently
If insufficiently
charged
When the watch is exposed to light, the Quick Start Function will begin operating
and the second hand will start moving. The correct time can be set once the watch
is fully charged.
If insufficient charge continues
If insufficiently charged and time is set

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The second hand changes to a two second
interval movement to indicate insufficient recharging.
Even in such a case, the watch keeps correct time, but
about 4 days after the two second interval movement
begins, the watch will stop.
After exposing the watch to light, recharging takes place
and the watch returns to one second interval movement.
Two second interval
movement
2 sec
2 sec
Quick Start Function
The watch will stop if it is completely discharged.
It will begin to operate soon after it is exposed to light.
(However, the time to start may vary according to the brightness of the light.)
Overcharge Prevention Function
You can recharge your watch without worry.
Once the special energy storage cell is fully charged, the overcharge prevention
function comes into operation and prevents over-charging of the energy storage cell.
Insufficient Charge Warning Function

D. CARE AND HANDLING DURING CHARGING
Notes on Use
To maintain optimal performance, be sure to expose your watch to light
regularly.
Please note that if you wear long sleeves, your watch may be hidden from light
and may result in insufficient charging. As such, additional exposure to light may
be necessary.
•When you take your watch off, be sure to place it in as bright an area as
possible.
Notes on recharging
•Avoid recharging your watch in areas of high temperatures (over about 60 °C /
140 °F
), otherwise the sensitive components of the watch may become damaged.
(e.g.) Incandescent lights generate heat sufficient to damage your watch. Be
sure to keep the watch at least 50cm (20inches) away from the bulb so
no damage occurs. We do not recommend the use of Halogen bulbs for
recharging.
Never place your watch on the dashboard or rear deck of a vehicle as the
heat generated in these areas can damage your watch.
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E. ABOUT THE RECHARGEABLE CELL
Unlike ordinary watches, the special rechargeable cell used in your watch
does not need regular replacement. This is a clean energy cell that will last
the life of the watch.
CAUTION:
The rechargeable cell should last the life of the watch. Never allow anyone other
than an Authorized Service Center to replace this cell. The movement is designed
to operate with only the original rechargeable cell. If an alternate cell is installed,
such as a conventional battery, the battery may become overcharged resulting
in damage to the movement and/or bursting of the cell, which could cause injury
to the user.
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F. TIME REQUIRED FOR CHARGING
Time required for recharging may vary according to the design of the watch
(color of the dial, etc) and operating environment. The following table will serve
as an approximate reference: (Table of recharging)
10
Illuminance
(lux)
500
Environment
Inside an ordinary
office
Time required
From the stop state to the
one second movement
60 hours
One day
usage
4 hours
Empty to full
1000
60-70cm (24-28in.) under
a fluorescent light (30W)
25 hours 2 hours
3000
20cm (8in.) under a
fluorescent light (30W)
8 hours 40 minutes 150 hours
10000 Exterior, cloudy 3 hours 12 minutes 45 hours
100000 Exterior, summer,
sunny 18 minutes 2 minutes 12 hours