Let me guess, your watch stopped running and you want to replace the battery yourself! For most Seiko watches, you can easily do this yourself if you have a few simple tools - and the right battery.
In this article, I will explain how you can always check beforehand what battery goes in your Seiko Watch, without having to open it first.
Step 1: Determinate which quartz caliber or movement is in your watch
Before we can look up which battery you need for your seiko watch, we need to know what exact caliber is in it. Seiko made hundreds of different movements and depending on the size, thickness, age a different battery will fit and suit.
Turn your Seiko around and look for the 8 digit code (4 digits - 4 digits)
The first 4 digits of the reference will be the caliber code of your movement, in the picture below the red arrow points to the caliber.
Use the Mizeni Database to find your caliber & battery
That's all we need right now! Now, you could look for the manual of this specific movement, or go through a list / PDF that has ALL calibers and battery types, but this is a waste of time!
There is a website called Mizeni that has pretty much every quartz caliber ever made by Seiko listed.
If we look up the caliber with Mizeni, in this case '7433' it will just tell your straight away what battery goes in it!
When I look up the battery type, there's a lot of choices!
Basically, every battery producer has their own coding / names for batteries which are interchangable in standard.
My personal view is that I aim to use Seiko's standard: Seizaken Batteries, as much as I can. But, sometimes they are expensive, or not available.
In that case, make sure to look for the right type of battery. There is 3 types of chemistry in batteries:
- Silver Oxide
- Alkaline
- Lithium
In the above example, it says SR721SW is needed. SR Stands for Silver Oxide. So make sure you purchase a Silver Oxide battery!
There is also two suffixes, SW and W. SW stands for "low drain" and 'W' for high-drain.
Generally speaking, a quartz watch is a low-drain device and you can/should use a SW battery because it will have a lightly longer life.
In some cases, for example when you have a very advanced movement, or your watch has a backlight, the manufacturer of the watch might recommend a 'W' battery.
There is no harm in using a 'W' battery in a general watch.
Don't cheapen out on batteries! Go for the established brands!
There is many brands producing batteries, and even though most batteries are not expensive, there is a big difference. You could purchase 10 no-name batteries for one normal brand battery.
Do not cheapen out on cheap, chinese batteries! Not only will you most likely have to replace it sooner than with an established brand, you can damage the watch if the battery starts leaking. A leaking battery is the quartz-movement watchmakers nightmare.
Also, a jeweller or watchmaker generally charges starting at 7,5 - 10 euros for a battery change (depending if you want to pressure test, new gaskets too etcetera, price will be higher) so you are already saving money by doing it yourself.
From my experience, stick with the known brands Seizaken, Renata, Maxwell, Murata for watch batteries.
Also, batteries get much cheaper if you purchase them in higher quantities. Most battery resellers offer big discounts if you purchase in a box per 10.
Where to buy watch specific batteries?
Most watch part wholesalers have a a wide array of batteries available, like Boley, Beco Technik, Esslinger, Cousins. You can also just type in the battery you need in google, amazon, ebay and many hits will pop up. Generally speaking, batteries are overpriced on marketplaces.
Personally I just purchase them from a battery reseller in my country, because it saves on shipping costs and they have the exact same batteries as watch part wholesalers.
What tools do I need to open my Seiko Watch?
That's a whole different question - and I've written a separate in-depth blog about what tools you need to open any kind of Seiko caseback so you can replace the battery of any seiko watch yourself. Find the article here.