General Reference For Charging Times; Charging Procedure; Charging By Exposing The Solar Cell To Light - Citizen B51 Instruction Manual

5. General Reference for Charging Times

(Case of Charging by Illuminating Solar Cell Only)
Charging times differ depending on the watch model (type of face, etc.). The charging
times shown in the table below are meant to only serve as a rough indicator of required
charging times.
Luminance Charging
Environment
time for 1 day
(Lux)
of operation
Typical office 2 hours
500
Under a fluorescent
lamp (30 W) at a
45 minutes
1,000
distance of 60-70 cm
(24-28in.)
Under a fluorescent lamp
15 minutes
3,000
(30 W) at a distance of
20 cm(8 in.)
Cloudy day 4 minutes
10,000
Under direct sunlight
2 minutes
100,000
on a summer day
Full charging time: Time from the state in which the watch is stopped until it is fully charged
Charging time for 1 day of operation: Time required for the watch to run for 1 day using the
normal time display (1-second interval movement)
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Charging time
Charging time from Full
stop until 1-second
charging
interval movement time
*The charging
37 hours, 30 minutes 335 hours
time indicated
refers to the
15 hours 143 hours
duration of
continuous
illumination.
5 hours 45 hours
13 hours
1 hour, 30 minutes
2 hours, 30
30 minutes
minutes

6. Charging Procedure

If the second hand of the watch is moving in 2-second interval movement or has stopped
due to undercharging, recharge the watch either by exposing the solar cell to light or by
swinging.
A. Charging by Exposing the Solar Cell to Light
* Expose the surface of the solar cell to a fluorescent lamp, incandescent light or sunlight
to recharge.
* If the watch is ordinarily concealed from the light as a result of wearing long sleeve
shirts and so on, the watch will be susceptible to becoming undercharged as a result of
not being exposed to light. Try to place the watch in as bright a location as possible
when it is not worn.
* When there are few opportunities for exposing the watch to light, the watch can also be
recharged by swinging in the manner described below.
[Precautions When Charging by Exposing to Light]
* Avoid charging the watch at high temperatures (approx. 60°C/140°F and above) since
allowing the watch to become overheated during charging can lead to a malfunction.
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