Seiko V181A Technical Manual

PARTS LIST / TECHNICAL GUIDE

ANALOGUE SOLAR Cal. V181A

[SPECIFICATIONS]

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Item

Cal. No.

V181A

Power reserve

Driving system

Additional function

Crown operation

Loss/Gain

Regulation system

Number of jewels

Normal position

1st click position

Current consumption

Gate time for rate measurement

Power supply

Motion of the second hand

Coil resistance

Power
generator

Rechargeable
battery

Operating
voltage range

One-second intervals

Stepping motor 1 piece

Movement

Diameter

Outside: 20.0mm
Casing : 19.4mm

Height: 2.20mm

3 hands (hour, minute and
second hands)

Instart-start function
Energy depletion forewarning function (The second hand moves at
two-second intervals.)
Overcharge prevention function
Electronic circuit reset function
Second hand stop function

Free

Time setting

Monthly rate: less than 20 seconds (worn on the wrist at
temperature range between 5 to 35 degrees Centigrade)

Use 10-second gate

Nil

Solar power generation system

Movement : less than 0.80 μA

Circuit block: less than 0.40 μA

Coil block: 1.80 - 2.20 K

Ω

MT616 Manganese titanium lithium rechargeable batter y

0.45V - 2.20V

From full charge to stoppage: Approximately 2 months

2 jewels

SPECIFICATIONS

2/18

Cal. V181A

FEATURES

The Cal. V181 is an analogue watch with a solar power generation system.

l Solar power generation system

The watch operates while charging electricity by converting light received on the dial to
electrical energy. It lasts for 2 months af ter full charge.

l Energy depletion forewarning function

When the energy stored in the rechargeable battery is reduced to an extremely low level, the

second hand starts moving at 2-second intervals instead of the normal 1-second intervals.

l Instant-start function

When the watch is exposed to sunlight or strong ar tificial light (of more than 1,000 lux), it will
star t operating immediately with the second hand moving at 2-second intervals.

l Guideline of charging time

Environment/ Light source Illumination

(lux)

Time required
for full charge

Time required
for steady
operation

Time to charge
1 day of power

60W 60cm/Incandescent
light

500 110 hours 8 hours 100 minutes

General offices/ Fluorescent
Light

700 82 hours 6 hours 75 minutes

30W 70cm/ Fluorescent light 1,000 60 hours 4 hours 55 minutes

30W 20cm/Fluorescent light 3,000 20 hours 1.3 hours 18 minutes

30W 12cm/Fluorescent light

5,000 10 hours 33 minutes 9 minutes

30W 3cm/ Fluorescent light 10,000 5 hours 15 minutes 5 minutes

Cloudy weather/ Sunlight 10,000 5 hours 15 minutes 5 minutes

Fair weather/Sunlight 100,000 2.1 hours 7 minutes 2 minutes

The above table provides only a general guideline.

It is recommended that the watch be charged for as long as the charging time according to the
column "Time required for steady operation" in this table in order to assure the stable movement

of the watch.

l Caution for charging

When charging the watch, do not place it too close to a photo flash light, spotlight, incandescent
light or other light sources as the watch temperature will become ex tremely high, causing damage

to the parts inside the watch.

When exposing the watch to sunlight to charge it, do not leave it on the dashboard of a car, etc.
for a long time, as the watch temperature becomes extremely high.

While charging the watch, make sure the watch temperature does not exceed 50 °C.

PARTS LIST

Cal. V181A

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28

28

SOLAR CELL UNIT

Large : 4025543

Small: 4025575

CONTACT SPRING FOR
SOL A R CELL UN I T
4246644

CASING RING

Large : 82840960

Small: 82840940

EARTHING SPRING

4281503

DIAL WASHER

0491735

HOUR WHEEL

0271500

[SOLAR POWER GENERATION MECHANISM]

Order of disassembly:

Order of assembly:

1

1

1

2

3

4

5

6

Lubricating : Types of lubricant

Watch Oil AO-3

Watch Oil AO-2

Lubricant quantity:

Normal quantity

Cal. V181A

PARTS LIST

4/18

SETTING STEM
0351500

MAIN PL ATE
0100978

RECHARGEABLE
BATTERY UNIT

302729Y

CIRCUIT BLOCK
COVER SCREW

0022247

CIRCUIT BLOCK
COVER

4457923

CIRCUIT BLOCK
4000656

TR A I N WHEEL
BRIDGE

0125907

FOURTH WHEEL
0241929

THIRD WHEEL
0231904

FIFTH WHEEL
0701904

STEPPING ROTOR
4146907

MINUTE WHEEL
0261907

SETTING WHEEL
0281904

TR A I N WHEEL
SETTING LEVER

0391890

COIL BLOCK
4002907

ROTOR STATOR
4239908

SETTING LEVER
0383176

YOKE
0384890

CLUTCH WHEEL
0282890

CENTER WHEEL
0221929

BATTERY
CONNECTION(+)
4268656

RECHARGEABLE
BATTERY UNIT SCREW
0022247

26

27

24

Please see the remarks on the following pages.

7

8

9

10

11

12

13

14

15

18

19

16

17

28

[BATTERY AND ELECTRONIC CIRCUIT

- GEAR TRAIN MECHANISM AND STEPPING MOTOR ­SETTING MECHANISM]

20

21

22

23

25

PARTS LIST

Cal. V181A

5/18

l

How to find the correct parts, if not determined by 4 digit caliber number

Following parts are determined based on the design of watches, such as hands height, dial color,

and design of cases. Please refer to the SEIKO WATCH PARTS CATALOGUE in order to choose

corresponding parts.

Casing ring Large: 82840960 Small: 82840940

Setting stem 0351500

*

For screw down crown models, the stem is assembled to the crown and is not available

separately.

Note:

Solar cell unit Large: 4025543 Small: 4025575

* When ordering this par t, make sure which size you need by visually obser ving the disassembled

part. Our parts catalogue currently shows both sizes under the same model

.

4

1

24

Cal. V181A

PARTS LIST

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l Tools and consumables required for disassembling/reassembling

• Movement holder

UNIVERSAL MOVEMENT HOLDER (S-682)

• Watch oils

SEIKO watch oils (AO-3 and AO-2)

AO-3

AO-2