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Chronomaster: 4 1/2 sec band over 5 years with new movement; what do I do now that batty is dead?

1770 Views 13 Replies 7 Participants Last post by  Hans Moleman
I bought my Citizen Chronomaster through Katsu Higuchi in Japan in 2007. Subsequently I posted much data here at Watchseek showing how the watch rapidly sped up over time and way out of spec, repeating that bad behavior after going back to Japan for service. Finally Higuchi decided it needed a new movement and in fact after that it performed MUCH better. I'm enclosing a graph showing that in the ~5 years it ran on its latest battery the watch stayed within a 4 1/2 second band compared to UTC, although that would not have been true for much longer.

But now the battery is dead and the watch is out of warranty. Higuchi did not reply to my last request for information about how to get the battery replaced and the watch regulated.

I have two questions for you better-informed people.

1) How can I get the job done by Citizen, presumably in Japan?

2) I can replace the battery myself, and grease the o-ring. I can certainly NOT regulate the rate, and beyond that I'm worried that the rate and TC parameters might be stored in volatile memory and would be lost if the battery is changed. Does anyone have experience changing the A660 battery at home?

Any help will be greatly appreciated!
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The change in rate (aside from seasonal temperature fluctuations) may have been due to either crystal ageing or drop in battery power. Each of these things has been known to have an effect on rate and of the two I believe a dieing battery is by far the more commonly reported problem.

If you change the battery yourself, you might see the rate return to normal.

On the other hand, if you send it back to Japan the watch will be gone for several months at least and from my personal experience I have absolutely no faith in Citizen's ability to regulate the rates of their top tier watches.
I've heard quite a bit about Citizen service falling down. How are Seiko with servicing their GS series HAQs?

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I haven't had to send a GS in for servicing, yet. I find it easy to replace the battery on a GS by myself and even easier to adjust the rate.
I can't help with advice on Chronomaster battery replacement.

I can help with an explanation for the disappearance of the 2 seconds.
They were caused by a failure to move the seconds hand. Once the rotor failed to move the first time, it was in the wrong position for the subsequent stepper pulse. The subsequent pulse failed to move it as well. Two seconds were lost.

The stepper motor needs a positive pulse to move the rotor to the North. And a negative pulse to move it South. And for that to work, the rotor needs to be in the proper position so that it can move North or South.

The new VHP's have this thing to pick up on those hick-ups and correct for them at a later stage.

Glad to see that your insistence on proper regulation has payed off. Eventually.
Except once to get Citizen Japan to regulate my watch, I have the battery changed locally.
Can you post a picture of the watch?

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I'm not sure what you have to loose by changing the battery yourself, your only concern would be introducing dust into the case and movement. If you change it and it returns to normal you're done.

I doubt if there is a unique TC curve for each watch, that it would be on the volatile memory would probably be even more unlikely. As far as the rate, possibly, but again probably more fixed because it just wouldn't make much sense to put it in the volatile memory.

If after the battery change, the rate requires regulation, contact your regional support center and ask them how to proceed. Like you said the watch is out of warranty, why incur costs and time before you determine you have to?
Thanks, guys, for your comments. And Hans, for explaining why my Citizen lost two seconds and not only one. I suppose that this is more likely to happen when the battery has weakened.
I see that the Grand Seiko has a mechanical control for rate adjustment. It's not clear to me whether that changes an internal digital value or an analog trimcap, but in any case it is nicely accessible. The online photo of the A660 movement shows no access to the inside other than by several probe-able electrical contacts. I'm not ready to try to guess how to use those.

Tom, here is an old photo of my Chronomaster on my timing setup. It looks good as new today after being worn for most of 12 years.

Batteries are arriving from Amazon on Tuesday, when I will install one unless something changes my mind before.


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If you're doing it yourself, I've got one tip.

The last battery change, I made sure to properly grease the o-ring. That made all the difference.
Closing it was that much easier since you don't have to work against the friction.
And you're sure the rubber sits properly all the way round.

Lubricant meant for o-rings obviously.

You'll be surprised why you bothered with sending it to Japan in the first place.

Still love your inventive rate measuring technique.
...I see that the Grand Seiko has a mechanical control for rate adjustment. It's not clear to me whether that changes an internal digital value or an analog trimcap, but in any case it is nicely accessible...
The rate adjustment of the Seiko 9F is digital ("changes an internal digital value").
OP kind of curious what battery is in your watch, and if it is possible, do you plan to upgrade from the original equipment to something better. Again I'm not sure what it came with in 2007, but if it came with a 40 mAh, have you considered going up to 55 mAh to gain a little more battery life? I doubt that it would affect the rate, at least it doesn't seem to on ETA movements.
Ok, I replaced my Chronomaster battery. The last person to replace the back in Japan torqued it down very hard; I needed to make a simple but sturdy jig to hold the watch case when I removed the back.

Anyway, in the few days on the new battery the watch has been running fast at an average of about 4.1 seconds/year, worn 24 hours per day except while showering or measuring. As is my habit, I include a graph. The variation in slope among the segments may be due to ambient temperature changes.

Thanks for your comments and suggestions! Text Font Line Rectangle Parallel

wbird: hmm, I didn't look into this. I just replaced the battery with a drugstore Duracell 370/371. Oh well, when this cell runs out I'll probably be ready to set the time again anyway.
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Another thing learned.
Well done Sir!

You see those Breitling ads for their service. Clearly meant to intimidate.
No, you don't need an operating theater to change a battery. That is, unless you decide to swallow the battery.
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