If you replaced a battery with a new one, how long can you expect the watch to run before it needs a new battery replacement again? Judging from our customers’ questions when they bring a watch into us for a battery replacement, there is a lot of confusion about how long do watch batteries last.
Are there different types or grades of watch batteries? Do jewellers offer better batteries than cheap batteries from stores? What about the really cheap watch batteries like you get in a strip in the 99p or 99c shop – are they just as good?
After all, some jewellers charge upwards of £10 for a new battery replacement (we charge £5). Is it because they use better batteries?
In this article, we’ll try to answer all these questions. You’ll probably learn some fun facts about identifying watch batteries too!
How Long Do Watch Batteries Last?
We’re not being evasive when we say, “it depends”. It really does.
It depends on the battery (more on this later).
It also depends on your watch.
Age of Your Watch
An older, less efficient watch that hasn’t been serviced regularly (or at all!) may drain a battery more quickly than a new watch. Watches that are older and haven’t been serviced won’t have as much ‘lubricant’ in the movement and so it will be harder work for the movement to function as it should.
The Number of Functions Your Watch Has
Quite often, watches with more than one function will have more than one battery. Analogue and digital watches (including those with flashing dials like some Fossil watches had) will regularly have one battery for the analogue part and another battery for the digital part. The same is true of sports watches with multi-functions, like alarms, or watches with lights.
A watch with more functions (like a chronograph watch with second-hand, dual time, stopwatch or watches with alarms) will use more “energy” than a watch without extra functions.
Types of Batteries in Different Watches
A quartz watch will take a standard button cell battery (we’ll talk about types of batteries later) or a lithium battery.
A Solar watch will have a rechargeable battery which could well last up to 12 years. This is the same for Seiki Eco-Drive watches – these need rechargeable batteries which are more expensive than your normal button cell batteries (although they appear to look the same, they are not).
A Kinetic watch is a type of hybrid watch. It has a movement that runs with a battery and has the accuracy of the quartz watch, but it is also powered by actual movement. The movement of the watch on your wrist will produce electricity in a tiny generator that recharges the battery/capacitor.
A Smartwatch will use lithium, rechargeable battery. The amount of time the watch can run before needing to be recharged again will vary on the manufacturer. You will get a lot longer running time out of some brands than others.
A new watch may get anything from 2 to 5 years before the battery needs replacing. Older watches and subsequent battery replacements will probably need replacing after a year or more. A year or two is about standard.
How do you know if your watch battery needs replacing
Some watches will slow down when the battery is getting low, some watches will stop and start, other watches will just suddenly stop.
Some watches have a Battery Power Indicator. This is when the secondhand jumps forward either two or five seconds at a time, and it’s a warning that the battery is getting low and an indication that it should be replaced.
The Different Types of Batteries
The battery that should go in your watch will be of a particular size and that is what it must be replaced with.
There are Silver Oxide batteries, Alkaline or Lithium batteries.
A lithium battery is a larger, flat, coin-like battery and the new, replacement battery must be the same size and depth (indicated by a number on the battery) as the one that is removed. These are 3-volt cells. You cannot put a lithium battery in a watch that takes a button cell battery – apart from anything else, they are completely different sizes, but they are also a different voltage!
Lithium batteries are coded on their size and normally start with the letters CR (sometimes also BR), followed by four numbers.
A Quick Guide to Watch Battery Codes – the meaning of the Watch Battery Letters & Numbers.
After the prefixes, or initial letters (as already stated, this will be either ‘CR’ or ‘BR’ for a lithium battery), the first two numbers relate to the battery’s width in mm and the second two numbers are the battery’s depth (within a decimal place). A battery with code CR2016, for example, will be 20 mm wide and 1.6 mm deep.
Prefixes Used With Lithium Batteries
CR or BR
Button or Coin Cell batteries are much smaller than lithium batteries – like … you’ve guessed it … tiny buttons!.
There are many different sizes (both in width and depth). We keep about 25-30 different sized button cell batteries in stock in our jewellers, at all times. The two most used sizes are 377 and 364. We order these in multiples of hundreds, but every day we also use many of the other sized batteries.
Button or Coin Cell Batteries
Button Cell batteries are 1.5-volt batteries and are either Silver Oxide or Alkaline. These are interchangeable (although it is not advisable to use Alkaline batteries in watches).
Silver Oxide Batteries
Silver Oxide batteries are very stable and maintain a constant output.
Alkaline batteries have the same voltage as Silver Oxide but, once used, this voltage drops very quickly. Watches require a constant output of energy. So, alkaline batteries are not the best choice for watches.
Batteries that are sold in strips cheaply – in 99p or 99c shops – are normally alkaline batteries. Replacing batteries in your watch with these Alkaline batteries will power your watch and get it going, but in all probability, the watch won’t stay going for anywhere near as long as a Silver Oxide battery.
Quite frankly, it’s a false economy to use these alkaline batteries in your watch – particularly if your local jeweller doesn’t charge the earth for the watch battery replacement. (Jewellers have also got all the tools to remove the watch back safely and ensure a good seal when they pop the back onto the watch after replacing the battery).
In a similar way to Lithium coding, the button cell batteries have a number following the prefix letters. These generally indicate similar things to the lithium batteries – the width and depth of that particular battery. They often have two codes on the surface of the battery – a 6 or 7 digit code of letters and numbers plus a 2 or 3 number code. For instance, the SR626SW size also has the number 377.
The Prefixes used in Silver Oxide/Alkaline Batteries.
SR =Silver Oxide
SG = Silver Oxide
L = Alkaline
AG = Alkaline
LR = Alkaline
Button/Coin Cell Batteries also are followed by a suffix – either SW or W. The SW means it is suitable for Low Draining Devices and a W on its own is more suitable for High Drain devices.
Hence many watches with multiple functions, like a chronograph watch or a watch with a backlight will need a battery with the suffix W – this will feed the extra requirement for the power needed.
Battery Codes Explained…
The code for the battery SR626SW tells us the following …
|Silver Oxide||6 mm wide||2.6 mm deep||Low Drain Device|
How Do You Know What Battery Your Watch Takes?
Some brands of watches print the battery size needed on the back of the watch.
We find some customers when trying to replace the battery themselves and leave the battery out of the watch. It’s really helpful to keep the battery in the watch if you bring it in for a replacement battery (or keep it separately). This way we can immediately see what size battery you will need.
Reputable Watch Battery Brands
Renata watch batteries are one of the leading brands of watch batteries and are the brand we chose for most of our batteries. They have developed a 0% mercury battery selection. Most of the main Swiss watch manufacturer’s rely on Renata batteries to power their watches. These batteries are superb and have a shelf-life of 10 years or more.
Other good brands include Energizer, Duracell and Maxell.