Tuesday, December 07, 2010

DW-8201 Battery change

Yet another battery change. This time it is the turn of the Casio G-Shock DW-8201 Frogman. A couple of things first. This is not a step by step tutorial of how to do a battery change on a Casio G-Shock. Some expertise and experience is required if you want to do this yourself. 

Get out the tools. Since this watch has a screw-down case back, the screw-back case opener is required. Remember to use non-metallic tweezers for the battery change. 

The new battery. In this case the watch is fitted with a CR2016 3V battery.

The watch. Note the black display.

First we need to remove the straps as the edge of the straps overlap onto the case back. The straps on the Frogman is unique as it provides access to the spring-bars on one side of the strap.

Another view of the access gap.

As the access gap is narrow, use the proper size spring bar tool. 

The strap removed. If you notice there are two holes on the lugs. The larger hole is for the screw that holds the rubber outer case to the titanium case.

Here you can see the off-set strap attachment point. It is interesting to note that the spring bar hole has a metal sleeve.

Remember to store the straps and spring bars in a safe place.

Use the screw down case back tool to open the case back. Make sure it is square to the case back. Some people tape the case back with tape to prevent scratching in case the tool slips. 

OK, I know that the Frogman is the only G-Shock that is ISO 6425 rated, and inscribed on the case back  'DO NOT OPEN!' But I do not use the watch and since the watch is not fluid filled or gas filled, I guess it is OK for me to replace the battery. I, however cannot confirm or test the watch to 20 ATM (static) after the battery change. So if you are concerned about the ISO rating and do use your watch for diving, please send the watch back to Casio Service Centre.

The removed case back. I do like the WCCS engraving in the centre of the case back.

The inside of the case back. You can see the piezoelectric speaker.

The 1294 module. 

You can see the battery hatch holding the battery.

Another view.

You can see the metal plate and the rubber protector that protects the module from shock.

The tang on the metal plate. Remember its position. It sits in a slot on the module holder.

The notch on the metal plate and rubber protector. At the 11 o'clock position, you can see the metal tab that connects to the piezoelectric speaker on the case back.

The metal plate removed. The inside tang sits in a slot on the rubber protector. It acts as a locating tab.

The rubber protector. Remember that the dimples points to the case back. 

Another view of the module and rubber protector.

The rubber protector removed. You can see the slot at the 6 o'clock position where the inner tab on the metal plate sits in.

The module and the battery holder exposed and ready to be unlocked.

A closer view of the locking mechanism. It is a simple latching mechanism.

A side view of the locking mechanism. You can just make out the two fingers (3 o'clock) that hold down or locks the tab.

Don't forget to lubricate the rubber gasket. Also inspect the gasket for damage. 

Back to the locking mechanism. Just pry the tab and it will unlock.

A closer view of the tab. If you look at the 8 o'clock position, you will see the legend 'AC' and a hole next to it. This is to 'short' or reset the module once you change the battery. We will look into this later.

Side view of the battery holder and the locking tab. The 'AC' or reset hole is at the 6 o'clock position.

Another view of the tab.

A closer view. Also if you notice there are two prongs under the battery holder. This is the contact for the battery. You need to be careful when you remove the battery so that it does not get stuck to these prongs. The prongs can get 'stuck' to the edge of the battery. If you feel some resistance when trying to slide out the battery, it may be 'caught' by these prongs. Slide the tips of your tweezers below the battery to disengage the prongs from the battery.

The new battery ready to replace the old one. Use your plastic tweezers to handle the battery. Do not use your fingers as you may leave a coat of oil and cause corrosion.

Slide the battery in. Make sure it sits in the battery slot.

Another view. To lock the locking tab, just push it down until you hear a click. Make sure the edge of the tab is flush with the battery. To is to ensure both locking fingers are holding the locking tab.

Turn over the watch. If you see that the display is blank (as below) or that the display is erratic, this is normal. You will need to reset the module. You need to 'short' the metal piece inside the 'AC' hole to the back of the battery. The way I do it is to insert the tip of the spring bar removal tool into the hole and use a metal tweezer to touch the tool to the back of the battery. Hold for about 2 seconds and the reset is done.

The module is reset to its original factory setting. 

Once this is done and the module is confirmed working, just do the opposite and restore everything. Put back the rubber protector. Remember the dimples towards the case back.

Place the metal plate. Align everything to its proper place. Once everything is aligned, rubber gasket installed, put back on the case back and you are done.

Adjust the watch to the correct time, day and date.

And there you have, how to change the battery on a Frogman. Remember the steps may differ from G-Shock to G-Shock. 


  1. Dear Ivan,

    Nice Job on this Frogman battery change demo. Any idea how to change the GW-200 Frogs? Hopefully, can see your demo soon.



  2. Hi Chow,

    Welcome to the blog. With regards to the GW-200 Frogs, I don't think I will change the batteries on those. These Frogs are fitted with the Tough Solar Modules, thus are fitted with rechargeable batteries. I don't think the batteries are commercially available. So I would send the watch to the service center if there is a need to change the battery as the problem could be the module and not the battery.

    Best regards,