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About charging

How to charge the watch

Expose the dial to light to charge the watch.


To ensure optimal performance of the watch, make sure that the watch is kept sufficiently charged at all times.


Under the following situations, the energy of the watch is likely to be depleted, resulting in stoppage of the watch:

The watch is concealed under a sleeve.

The watch is used or stored under conditions where it cannot be exposed to light for a long time.

When charging the watch, make sure that the watch is not heated to a high temperature. (The operational temperature range is between -10°C to +60°C (14 ºF and 140 ºF).)

When first using the watch or starting to use the watch after it has stopped because of the energy depletion, sufficiently charge the watch referring to the table on the page at the right.

Standard Charging Time

Charge the watch using the times below as a guide.

GPS signal reception consumes a lot of energy. It is necessary to charge the watch by exposing it to light so that the indicator hand points to the “middle” or “full” position. (If the charging status is displayed as “low,” the reception will not start even with manual GPS signal reception.)

lx (LUX)

Light source

Condition (Example)

From the state where the watch is stopped (not charged)

In the state where the hand moves (the watch is charged)

To fully charged

To one-second interval movement is secured

To move for one day


Fluorescent light

General offices



3.5 hours


Fluorescent light

30 W 20 cm

420 hours

12 hours

1 hour


Fluorescent light

Cloudy day
30 W 5 cm

115 hours

4 hours

15 minutes



Sunny day (Under the direct sunlight on a summer day)

50 hours

1.5 hours

10 minutes

The figures of “Time required for charging the watch to start moving at one-second intervals” are estimations of time required to charge the stopped watch by exposing it to light until it moves at steady one-second intervals. Even if the watch is partially charged for a shorter period, the watch will resume one-second- interval movement. However, it may shortly return to two-second-interval movement. Use the charging time in this column as a rough guide for sufficient charging time.

The required charging time slightly varies depending on the model.