How to Replace a Watch Battery in Your Watch Tips on Changing your Watch's Battery So how do you replace a watch battery in your watch? Here are some answers to some frequently asked questions:- Do I need a special tool to remove the watch back? First you need to determine if the watch is a snap back type or a screw back. If the watch back has a series of equally spaced slots (usually about 6) around it's perimeter, then it is a screw back and you will need a special tool in most cases. You can sometimes remove a screw back 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. We can sell a tool for this purpose, but they are 6.50 each and so you need to weigh up how many times you will be removing the watch's back to know if it's worth buying one. The back from snap back watches can be removed with a blunt pen knife. If you look carefully around the edge of the watch casing you should see a small indent in the cover. This is where you start with the blunt pen knife, working your way around the edge twisting the knife gently as you go. Eventually the back will snap out of the watch casing. Do I need to replace the rubber seal? Well, you should really, but we bet most high street jewellers who change a battery for you won't do this. It depends if you want the watch to be waterproof or water resistant again and if you are going to use it in conditions where it will be exposed to water or dampness. If this is the case then you need to take the watch to a jewellers, make them aware of your requirements and then it is likely that they will send it off to the manufacturer to have the battery changed and the watch pressure tested. If however, your watch is not exposed to these conditions then it is likely that changing the battery yourself will leave you in no worse a position than had you taken the watch to a high street jewellers and got them to change the battery for you. They will often say, after changing the battery, that they cannot guarantee that the watch is now waterproof but still charge you around £6 or more. My watch is waterproof, how can this be guaranteed after changing the battery? The bottom line is that the watch is likely to have to be sent away unless you can find a jeweller or watch repairer carrying the special piece of equipment required to verify that the watch is still waterproof after the battery change. The test equipment required to do this only costs a couple of hundred pounds and we are surprised that most high street jewellers don't have it. It 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. This is what is likely to happen when the watch is "sent back to the manufacturer" when you take it to the jewellers and ask that the battery be changed, but you want it to be waterproof again. I have the back off the watch, but it seems that I need to remove a screw in order to get the old battery out. Be careful here. This may or may not be the case. In some watches it is merely a case of loosening a screw which will allow a clip to be moved to the side enough to allow the battery to be levered out. Once the screw is removed they are rather difficult to get back in, although not impossible. Just don't go trying it when you have had a glass or two of wine that's all. So, check that you really do have to remove a screw in order to remove the battery. In most cases it is a merely a question or loosening a screw and on some even there is no screw at all, just a clip which when prised back slightly will allow the old battery to pop out. I have a snap back case and I am having trouble getting the back on. Some case backs are tight. 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. The best way to put the cover back on 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 with both thumbs, applying 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. Basically 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. I have replaced the battery but the watch isn't working. 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, believe it or not, actually got them going again. It is always best to replace a battery in a watch as soon as the watch stops working. I have replaced the battery in a LCD watch, but the display is all funny. If this happens then most of these watches can 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 is a hole into which you place one leg of a pair of metal tweezers and the other leg touches the main movement housing (creating a temporary short circuit). This should reset the display. Top of Page This page or any part of this web site should not be copied without permission. © WatchBattery 1999