Replacing a Seiko Kinetic Watch Battery


I’ve owned a Seiko Kinetic model 5M62 watch for about 8 years and I really liked the fact that it never needed batteries and would run for days without winding. The Kinetic watch is self-winding, and instead of using a spring to store the energy, it converts the mechanical motion into electricity and stores it instead. This gives it the convenience of a self-winding watch along with the accuracy of a quartz movement. However, a few weeks ago I noticed that it would stop running if I took it off for a few hours. Sometimes, when I was just typing on the computer and not moving my wrist around, it would stop running. Below is a picture of the watch.

Seiko Model 5M62

I figured there was something wrong with the energy storage system, possibly a dead battery or bad capacitor. After a web search, I found out that the watch does have a battery, which is sometimes referred to as a capacitor, but it is indeed a battery. All rechargeable batteries eventually lose their ability to hold a charge and after 8 years, this one had simply worn out. The problem with changing it is that the Seiko Kinetic battery is not one of those standard watch batteries that you buy in a store and easily change by yourself. However, I found that it could be purchased from vendors on Ebay or other on-line websites like for around $20.

In our disposable society, I’m sure this issue could have been an excuse to go shopping for a new watch. But once you become attached to a watch, and this one is water proof so I hardly ever take it off, it sort of becomes a part of you. I hated the thought of replacing it, especially because I felt it had many more years of service.

I started reading a few of the websites that talked about replacing the battery as a DIY project, but wasn’t sure if I was up to the task or had the necessary tools. I never had taken the watch apart and looking at the back of it, I didn’t think it would simply pop off like my previous watches that had user-replaceable batteries. I talked with the jeweler where I bought it and they told me that they would have to send it away for repair and thought it might cost $65 or more to replace the battery. The local jewelery repair shop had a similar assessment. So, being an adventurer and inveterate fixer, I decided to do it myself.

You can see from the image below that the watch had notches on the back of its case. This meant that it needed a special case opener wrench.

Watch with notches requiring a watch wrench

I decided to get a Jaxa style opener (shown below) which clamps down on three notches since it seemed like it would do the job better than the openers that only grabbed the case on two notches. These can be found on the Internet or at Harbor Freight for less than $10.

Seiko watch case wrench

To make things easier, I decided to remove the watch band. Most of the watches I’ve owned had spring-loaded pins that were pretty easy to remove, but this model had pins pressed in that held the watch band in place. I was able to push them out with the tool shown below.

removing the pins from the Seiko watch band

I used a paper towel to protect the watch and gently gripped it in a vice and was able to unscrew the back with the watch opener. It took a fair amount of torque to loosen the case back. In the image below you can see what it looks like inside. The battery is the brass-colored part in upper side of the image below. To get to it, you need to remove three very small screws. I had several small jeweler’s screw drivers around the house, but these screw slots are so tiny that I found it necessary to use a file on one of my screw drivers to make a very sharp tip in order for it to fit in the slots of these screws.

inside view of Seiko Model 5M62

The center screw holds the winding weight and gear in place. These items can only go one one way as the shaft is keyed. Actually, they can go on two ways, but both ways are correct. However, you can put them in upside down, so pay attention to how they are installed as you remove them. The gear must mate up with a smaller gear so make sure that it does before installing the winding weight and screw.

removing seiko watch rewiding weight

When you get all the parts out, they look like the image below. There are 3 small screws, the winding weight, a gear, a red mylar insulator, a battery hold-down clamp, and the battery. To re-assemble them, just (carefully) put them back together they same way you took them apart. You’ll find a pair of sharp tweezers useful to handle the screws and other parts.

disassembled view of seiko 5M62 watch battery

Here is the package I got from an online retailer. It came with a red mylar insulator, a hold-down bracket, and the Maxcell TC920S battery.

Seiko 3023-5MZ replacement battery

In addition to the tools mentioned above, I also used the magnifying headset shown below which I highly recommend. I think that the magnifying headset (with built-in LED lights) was instrumental in allowing me to work on such a small device. They can also be found on the Internet for less than $10.

lighted magnifying headset

If you’ve stuck with me this long, I’m going to give you a bonus. I mentioned that I had owned the watch for 8 years so now I have a confession. I always wondered what the push-button at the 2-o’clock position was used for. Sometimes it would advance the second hand 5, 10, 20, or 30 seconds and then it would sit there and stop. Then it would start running after the time had caught up with it. I had no idea why it did this because I had never read the owner’s manual and don’t even know if I still have a copy of it. So, in case you’re wondering, here is a copy of the page from the owner’s manual I found online that explains it (hint: it’s a sort of ‘gas gauge’ for the battery):

Seiko reserve indicator explanation

Incidentally, when the watch battery had begun to fail, it was impossible to get the reserve indicator to advance the second hand more than 5 or 10 seconds even after vigorous winding. Now with the fresh battery, it jumps forward 30 seconds whenever I push it.

Would you like to know how to correctly wind the watch and how much it takes to keep it moving for a day? If so, here is the explanation, again from the Seiko manual:

winding a seiko kinetic watch

It would appear that if you walk more than 720 meters (about 1/2 mile) you’ll impart enough energy to keep it going for a two days. Here’s another interesting tidbit: If you see the watch second hand jumping 2 seconds at a time, that means the battery is low and that you have less than 24 hours of charge left on it.

So, there you have it, a way to resurrect a watch that should last for decades. If you have one of these Seiko Kinetic watches sitting in a drawer gathering dust because of a dead battery, I hope my explanation gives you the motivation to get it working again for minimal cost. Please feel free to leave a comment if you have any questions or just want to share your experience with other readers.

Does it seem like too much trouble or beyond your skill level to do this repair? If so, you may want to get in touch with John Safranek at in Denton, TX or call him at 940-239-9888. He’s a Seiko Kinetic expert and performs these battery changes starting at just $49.95.

213 thoughts on “Replacing a Seiko Kinetic Watch Battery

  1. Thank you for this! I picked up a Seiko Kinetic at Goodwill for $49 in excellent condition except that it didn’t run for more than a few minutes. Half an hour’s work and it runs great with the new battery. Great!

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