Workshop: Battery Change and Clean of Omega Constellation

The Omega Constellation is one of the most popular ladies watch models out there. Nice combination of diamonds on the dial, two-tone bracelet and longevity make this a winner. Ladies tend to shun automatic or mechanical watches in general, unless of course they are made by Cartier or Rolex. But for around £1000-£1500 you can get a prestige pre-owned, Omega Manhattan quartz, with box and papers etc. It’s all good, as a new one is about £4500.

But after a few years it may need some TLC and  a new battery and this can come as a shock to many ladies used to paying £12 at Timpsons on their Michael Kors. Many Omega dealers will ask about £60-£90 for a battery change and it gets sent away to a service centre, often for three to six weeks, to accomplish this fairly simple task;. There is a better way, get an independent watch fettler on the job – like me.

What’s involved?

First I remove any excess dirt from around the caseback, this is because when I prise it open some may fall inside and get into the movement. Once that’s done, open using a special caseknife. This Omega features a battery held in place by a very thin metal strip and great care is needed when removing it. You have to turn the tiny screw to loosen it, then push it across – without causing damage.

Use tweezers to remove the old battery, bin it, then screw in the retaining nut again, as you don’t want to lose it. Now inspect and clean up the movement if needed. Obviously you need a magnifying glass or head loupe to see tiny gragments of dust or dirt in there. I use an air puffer as well.

This Omega takes a 321 sized battery and I always use Swiss ones, as it’s a false economy using other makes.

Very careful when fitting the new battery not to touch the copper coil near the battery holder. Quartz movements are quite delicate so tweezers and a steady hand is required. Once the thin retaining strip is in place then the nut just needs a turn and a half to secure it in position. Another go with the air puffer and use the special tool to press the caseback on again.

Omegas have a thin silicone seal on the back and this needs inspection for damage – and dirt – before refitting. It’s a tight fit, so again, extra care needed not to damage this sealing ring, as genuine Omega parts are expensive.

Now we begin to clean the bracelet. This one has gold plated sections on the linkage pins and the bezel, so attacking it with a power tool and a selection of polishing mops isn’t a good idea. The plating on modern Swiss watches is generally very thin, say 10 microns, compared to 40 microns 30 years ago. So it doesn’t take much speed or pressure to take the plating off.

I use cocktail stick, with a soft cloth wrapped around the end and dipped in a cleaning solution, to get into those tricky areas, like the sliding clasp mechanism. On this watch there was a build-up of hair and skin in there, plus gunk stuck to the quick release mechanism. Nasty. It takes time, about an hour, to deal with sticky skin based residue, then add some polish as well. But it’s well worth it.

Check out the before and after pics on the clasp.

Years of dust and dirt can get trapped in the slider clasp mechanism, and button actuator.
There’s no easy way to get all the residue out of the slider channels and push button section. Worth it though.

Final task is using Polywatch on the crystal and bezel area. I tend to use one cloth to apply, use a cross-hatch pattern and then circular motions on watch crytsals, or `the glass’ as some call them.

I’ve experimented in the past using a Dremel and soft mops, plus jewellers rouge, but the heat transfer on mineral or sapphire crystal means that you have just a few seconds before some watches are hot to the touch. That’s bad news. Even worse, you can crack the crystal as the heat makes it try to expand beyond the bezel. That’s my feeling anyway, slow and steady is best.

All done and a great looking watch, ready to wear.

If you have a watch problem, or you’re a trader looking for help with trickier jobs in your jewellers or ebay shop, then email me at

Advice, and estimates, are free.


4 thoughts on “Workshop: Battery Change and Clean of Omega Constellation

  1. I have one of these watches and when I opened it up the battery strap was not held in place and the holding screw is missing. I assume that whoever had replaced the battery before lost the screw. Do you know what the replacement screw size would be? Thanks.

    1. Can’t tell you the size or thread, but buying a joblot plastic tray of tiny watchmakers screws is probably the best bet. Off the top of my head it’s a very shallow little thing, only goes in about 1 turn, less than 1mm across. -al

Leave a comment here, we don't judge!Cancel reply