Seiko Caliber V147

The Seiko caliber V147 (actually marked V147A) is found in some Seiko solar-powered watches. This caliber is part of the Seiko Watch Corporation V family/series of solar powered movements. This caliber is still in production as of this post.

V147 VS V147A:

The movement in your timepiece may actually be signed with the caliber number V147A. As with most (if not all) Seiko movements, the trailing letter indicates the evolution or change-log of the movement, starting with A as the first release. Therefore, V147 is the same as V147A. As of this post, there is not a V147B, V147C, and so on.

V147 VS V157:

As of this post, it is still unconfirmed as to the differences between the Seiko V147 and V157. Both have central hours, minutes, and seconds. Both have a date which can be found at 3:00 or 4:00 depending on the watch model. Both have 2 jewels. Both are made in Japan. Both are the same cropped circle shape. Both use the same rechargeable capacitor/battery.

With all of that said, there is one big difference that CC has noticed: The V157 is available for purchase from parts sellers. The V147 does not appear to be available. Does this mean the V147 is replacing the V157? Not necessarily, since there are still current models with the V147.

Are the V147 and V157 interchangeable?

As outlined above, the two calibers appear to be very similar, however their interchangeability is still uninformed. If you have a broken V147 powered watch, you may want to test replacing it with a V157 before scrapping the watch – since you may not be able to obtain a new V147. If you do attempt to swap the V147 with the V157, please comment about it below, preferably with pics.

Accuracy:

Seiko claims that the caliber V147 will maintain accuracy of +/- 15 seconds per month at normal operating temperatures of about 5C to 35C (41F – 140F).

Battery Change:

The caliber V147 is a solar powered watch with a manganese titanium-lithium rechargeable capacitor. It is not a normal battery. The number is MT920, or more specifically: 302324Y. Order one here

Charging Times:

The chart below shows how long different lights sources can take to fully charge the cell in the V147. This ranges from 9 hours to 120 hours of constant light source. A full charge can last up to 10 months.

Instant-Start Function:

Instant-Start aka Quick-Start (both labels used by Seiko) allows the movement to start working almost as soon as you expose the watch to an adequate light source. In Seiko’s own words:

“When the watch is exposed to sunlight or strong artificial light (of more than 1,000 lux), it will start operating immediately with the second hand moving at 2-second intervals.” –Source

Also:

“If your watch has a second hand, when the instant-start function is activated after the watch is exposed to light, the second hand starts moving at 2-second intervals immediately, but the energy stored in the rechargeable battery is not sufficient. If the watch is turned away from the light, it may stop operating. It is not necessary to charge the watch fully. It is important, however, to charge the watch sufficiently, especially in case of initial charge.”

Interesting Note:

The instruction manual for the V147 is also shared with calibers V131, V145, V157, and V158. Sections of the manual are grouped for calibers V147, V157, and V158, indicating that these calibers are the most similar in the series. As we learned in the V157 caliber listing here, the main difference between the V157 and V158 is that the V157 only has a date, whereas the V158 has a day-date. As for the V131 and V145, they must have smaller capacitors and possibly different solar cells since they only hold 6 months of power on a full charge – compared to 10 months on the V147, V157 and V158.

Bonus: Here is another manual that combines calibers V110, V111, V114, V115, V116, V117, V137, V145, V147, V157, V158, V181, V182 & V187.

Additional Resources:

• Seiko official instruction manual is here