How to Replace a Watch Battery in Your Watch

So how do you replace a watch battery in your watch?

The instructions for changing a watch battery will depend on the type of watch you have: for example some watches have a back that screws off and some have a back that clips in place (snap back) and some backs are held on with individual screws. Once the back is removed then there maybe some type of battery retainer. This could be a plastic cover, a metal clip or a metal plate screwed over the battery. In order to cover as many of the situations that you are likely to encounter as possible we have compiled a list of some frequently asked questions:-

1. How do I open the watch case?
2. What is the correct battery for my watch?
3. How do I fit the battery?
4. How do I replace the watch case back?
5. Will my watch still be waterproof?
6. The digital display on my watch is not working.
7. My watch still won't go with the new battery.

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1. How do I open the watch case?

There are three main types of watch case - the 'snap back' type, the 'screw' type and watch cases where the watch back plate is held in place by small screws. Swatch watches have sealed cases which do not open, but have a battery port that can be opened for easy battery replacement.

	a) The snap off type watch back is flat to look at with a raised lip, usually located in the area where the watch strap is connected to the watch case. To remove this type of watch back you will need to insert a flat blade such as a blunt pen knife or our Snap back watch opening tool under the raised lip and prise the back off. Starting at the raised lip work your way around the edge twisting the blade gently as you go. Eventually the back will snap out of the watch casing. If using a pen-knife blade it is best to cover the hand holding the watch with a cloth or towel in case the knife slips. Click for more detailed instructions on replacing a battery in a snap back watch case.
	b) The screw type case back has a series of equally spaced slots (usually about 6) around it's perimeter. You can sometimes open a screw back case using a pair of snipe nose pliers in two of the slots, but unless the watch can be mounted safely in a small vice then this is quite difficult. It is probably easier to use a tool such as the Screw Back watch opening tool. Rotate the wheelon this tool until the two prongs fit snuggly into two of the opposing indents in the back of the watch and unscrew the back in an anti-clockwise direction.
	c) Watch backs held on with screws need to have the screws removed using a small screwdriver. It is a good idea to do this over a clean cloth so that you can ensure the screws do not roll away and get lost. Click for more detailed instructions on replacing a battery in a watch case with screws.
	d) Swatch watch cases do not need to be opened to change the battery. Instead the battery can be accessed via a battery cover which can be easily unscrewed using a small coin such as a 20p piece. Twist the coin a quarter turn anti-clockwise to open the battery cover. Lift off to reveal the battery. Click for more detailed instructions on replacing a battery in a Swatch.

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2. What is the correct battery for my watch?

In order to identify the correct replacement battery for your watch you will need to know the battery code. Sometimes this is imprinted on the back of the watch - as with Timex watches, but in many cases you will need to open the watch up to see the code on the battery. The code will take the form of either two letters followed by 3-4 numbers and possibly some more letters, or just 3 digits e.g. CR1216 or SR626SW or 364. Some battery manufacturers use other codes such as AG1 or 260-66.
Use our extensive cross reference table to find the equivalent code and correct battery for your watch. Alternatively you can simply type the battery code you have into the search box in the top right hand corner of the WatchBattery website page and it will take you to the correct equivalent battery.

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3. How do I fit the battery?

Once you have opened the watch case you will need to remove the old battery. There are a number of different ways in which batteries are held in place the watch movement. Sometimes they are held in by a spring clip, sometimes by a retaining bar, sometimes by a plastic cover. In some cases it will be neccessary to loosen or remove some screws to remove the ratining clip, in others the battery can be eased out of the battery compartment. Here are some examples of the types of battery retainers you are likely to see:

The top two photographs show different types of sprung battery retainers that will allow you to carefully tease the battery out from underneath the retainer. The third and forth photographs show battery retaining bars, which will need to be unscrewed until loose enough to slide to one side or remove in order to take the battery out. You may also need to remove the white plastic spacer shown in photograph four. This holds the watch movement in place inside the watch case and can simply be lifted out and put back once you have replaced the battery. A small screwdriver and a pair of tweezers are useful for this stage. Try to avoid touching the workings of the watch with your fingers as grease from your hands can effect the electronics in the watch.

Once you have removed the old battery, putting in the new battery is simply a reversal of the procedure above. Using the tweezers or other non-metalic tool ease the battery back into place and, if required, screw the retaining bar back in place.

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4. How do I replace the watch case back?

Before replacing the back of the watch first check that the watch is working, if it is then all is ready for you to replace the watch case back. When putting the watch case back on to the watch be careful not to loose or damage the rubber o-ring seal. This is important in keeping the watch water tight (see below).
With a screw back simply twist the back clockwise to screw it back in place.
With a back plate held on with screws, replace each screw and tighten gently so as not to strip the threads.
With the snap type watch back when placing the case back be sure that the indent on the cover lines with the winder. Most cases have a small indent to allow for the winder shaft. Some case backs are tight: The best way to deal with this is to place the watch face down on a flat protected surface - a mouse mat is ideal. Then with the case lined up with the back, push down use both thumb to apply even pressure to the case edge, making sure that one side doesn't get pushed further in than the other. With the cover being pushed evenly around its edge, it should snap back into place. If this still fails to get the cover back, then a jeweller would use a case press. This is a vice which comes with dies which fit over the back and one around the watch glass which means that the glass doesn't get broken when the vice is tightened. If you have a vice at home you may be able to improvise something which would give you the same thing or you can purchase one from us. We can offer a small back press for occasional use or the larger back press for frequent use.

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5. Will my watch still be waterproof?

As long as you have put the back on the watch securely and the o-ring is undamaged, the watch should retain its original water proof performance. Most high street jewellers will not be able to test the water proof performance of a watch on their premises, and so after changing the battery will not guarantee the water proof rating of the watch, therefore if you require your watch to be guaranteed water proof (such as a diving watch) it is likely that the watch will have to be sent away.
The test equipment required to do this costs a couple of hundred pounds and consists of a small tank which is half filled with water. The watch is suspended in the air space above the water and the tank is sealed. The tank is then pressurised with a hand pump to the required test pressure. Once at this pressure, the watch is lowered into the water and then the pressure released from the tank. If bubbles are seen coming OUT of the watch then clearly it is not water tight (well, not air tight actually). The seal will have to be changed again, the back retightened and the test repeated.

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6. The digital display on my watch is not working.

If the display on your digital watch is not working or not showing the correct display then it is likely that the watch needs to be reset. If you remove the back again, you should see some indication of a reset hole on the watch's movement. This is sometimes marked with the letters "AC" (All Clear). This needs to be shorted out against the case of the watch or the top of the watch battery. Using a paper clip or a pair of metal tweezers place one leg into the hole marked "AC"and touch the other leg against the main movement housing or the watch battery (creating a temporary short circuit). This should reset the display.

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7. My watch still won't go with the new battery.

The obvious one first. Is the winder (crown) pushed fully home? If so, has the watch been left standing with an old battery inside it for a long period of time? If this is the case it is likely that the watch is at fault. New battery failure is very rare, and if the watch has been left idle for a long period then it may never work again. Sometimes placing the watch in a warm place will "loosen" things up sufficiently to get the mechanism working again. We have fitted several new batteries to watches which have started for a while then stopped. Leaving them in a warm airing cupboard over night has actually got them going again. It is always best to replace a battery in a watch as soon as the watch stops working.