Casio MQA-100G Battery Change (Module 333)

By -

 Casio MQA-100G Battery Change  

 (Module 333)

Hello fellow Casio enthusiasts from around the World, I hope you are all well.

In this post I am going to change the battery in my MQA-100G. The watch had been running well (for over 3 years), until I noticed that the second hand had stopped running and the LCD section had become very faint leading me into a panic to change the battery. I had presumed (wrongly as it happened) that I had a spare battery but I couldn't remember which type it took so I checked an old post to see if I had mentioned it there, but I never mentioned it nor took a picture of the new battery. So that led me to open the watch up to see what type of battery the watch needed.

Let me begin...


The picture above shows the LCD section is very dim. The second hand has also stopped moving, leading me into panic mode to change the battery. I say panic mode because if the battery starts to leak (and it would have, which I will reveal later in this post) it would cause catastrophic damage to the delicate components in the watch leading to cause the watch to stop working. It was time to open the watch up and remove the old battery...


I removed the watch from it's display case and placed it face down on a soft towel.


I then took off the strap from the watch. I always find removing the strap makes it easy to work on the watch.


I then removed the watch back to reveal the battery that was clipped in place.


I then removed the plastic insulator and placed it to one side. I then loosened the small screw and unclipped the contact that holds the battery in place (of which I forgot to take a picture). With the battery removed from the watch, (which had not leaked, to my delight) I checked the new batteries I had in stock but I didn't have the correct type. 


As I didn't have the correct type cell to replace the old one, I replaced the back of the watch to prevent damage to the delicate components inside the watch and I started to look for a replacement battery online which lead me into...

A small chemistry lesson for myself


During my search for a new battery, I couldn't seem to find a standard LR927 battery, the only battery that was available was an SR927 battery so I did some research about the batteries. It turns out that the batteries are of an identical size, however the chemical make up of the batteries is different. The standard LR927 is an alkaline battery and the SR927 is a silver oxide battery. The standard LR927 is a 1.5 volt battery whereas the SR927 has a voltage of 1.55 volts. The difference doesn't stop there, apparently the silver oxide battery (SR927) has a more stable voltage output over its lifespan, where the alkaline battery (LR927) voltage tapers off or lowers during it's lifetime. Another downside to the LR927 (alkaline battery) is that alkaline batteries tend to leak when they are at the end of their useful working life, which is why I have ordered the SR927 (silver oxide) battery and why it was important (although I didn't know at that time that the battery in the watch was an alkaline) that the battery in my watch was removed as soon as possible. My panic of removing the battery quickly was justified and warranted. 

With my chemisrty lesson over, I placed an order for a Sony SR927 battery which cost me £3.25 including delivery. The battery should be her on Monday 14/9/26.

Until the battery is delivered, that is as far as I can go at the moment but please keep checking in for further updates.

Until I complete this post, please take care and continue loving your Casio watch.

casiotribe 2026




Hello, my name is Mr.B. I have started this blog as I have owned and loved (and still do) Casio watches for more than 40 years. I would like to explain the many reasons why I still own and wear a Casio Watch. I want to share details, upgrades and maybe a vintage Casio watch restoration post. I will also show you my humble, but very cherished Casio watch collection . I will also show my beloved and aged GW-M5600, I have owned and worn for the last 17 years. I will also be adding further watches to the collection and adding a detailed post for each and every watch. I also want to show you how to avoid a fake watch and what to look for when purchasing a Genuine Casio from any seller.

Comments

Post a Comment

Popular posts from this blog

Casio Watch F-91W Battery Change (Module 593)

By -
Image
Casio Watch F-91W Battery Change  (Module 593)  Hello fellow Casio enthusiasts from around the World. I hope you are all well. As the title suggests, I will be replacing the battery on my son's F-91W. He has had the watch from new and it is coming up to 6 years old. It's in excellent condition considering he has owned it since he was only 8 years old and worn it everyday since for school. The display is starting to fade, so it's high time I replaced the battery with a brand new one. The watch uses one CR2016 button cell, which cost me £3.50 (including delivery) for two cells and they are Duracell so a decent battery. I bought two as it's always handy to have new cells in hand if ever   required. Now that batteries have been delivered, it's time to get started. I know I should have removed the strap but it simply wouldn't budge from it's position and I didn't want to damage the watch as it is only plastic. I therefore left the strap attached to the watch ...
Read more

Casio AB-200 Databank Watch (Module 321)

By -
Image
Casio AB-200 Databank Watch (Module 321) 18/6/22 Hello fellow Casio watch enthusiasts, collectors and welcome to my post. As the title suggests, this post will be about the Casio AB-200 Data Bank watch. You may be aware (if you have read my previous posts), I have been looking for a good example for a long time now but finally, I have one on it's way to me. The actual watch is the one in the picture below and are the pictures I based my decision on to buy it. They are not the best pictures in the world and to be fair, the watch is not the best example of an AB-200 but it's the best I can afford at this moment. It is finished in silver with as best as I can see, has a white dial. I do believe the AB-200 silver came with either a white dial or a black dial. Whereas the AB-200G (gold) could come with a white, black or gold dial. To be honest I like the silver watch, both with either the white or black dial. I am just pleased to at last secured one! Another cool feature of this wat...
Read more

Casio AB-500 Data Bank Watch (Module 386)

By -
Image
 Casio AB-500G Date Bank Watch (Module 386)  23/1/2024 Hello fellow Casio enthusiasts from around the world, I hope you are well. If you have read the post I wrote about watches that I am always searching for, you may know I have had the Casio AB-500 data bank on my want list for many years. There are some examples still around and for sale. However, they are normally very expensive and in very poor condition as you could image a 30 years plus Casio watch would be.  Therefore an AB-500 in excellent condition will command a price tag of around £500.   Is it worth that kind of money, well, it may be worth that to an avid collector and I have witnessed such purchases. However, I could never ever justify spending that much money on any watch.  Anyway, as I was saying I am always looking for rare Casio watches, with the AB-500 near the top of the list. Well, 2 days ago I found one that I could justify spending the money on, but it is in need of a lot of TLC. In this ...
Read more