Dear All WatchUSEEK Members,
Sorry for my previous broken-link on the tip: "Changing CTL1616 Rechargeable Battery" This time I revised it directly on this forum for sure.
Watch: Casio G-Shock model MTG-900 - Japan Y
Battery: Rechargeable CTL1616
Failure: After 18 months from new purchase
CTL1616 can be ordered online, the price about 8 USD. The original battery has letter JAPAN without number 2 engraving. Avoid to short the terminals by using a plastic tweezer:
The easiest side for removing the band is Red-G button side from the left because on this side the holder covers on the most of the back-case:
Use a flat-screwdriver to push the screw out of the plastic link (this is a buffer-link between stainless steel links and the watch-lug). You may turn the screwdriver when pushing, but it is not necessary because this shaft has no thread. You may need a little liquid soap drop for lubricant.
The shaft is permanent attached to the watch lug. The rubber holder-link works in combination with 4 back-screws helps to hold the back tight.
After 4 screws are removed, slightly slide the back out off the other end. If slide too fast, three important springs will fly away, and causes two problems: no charge, no alarm eventually. Write a note for different length on each spring-location. (one is shorter than another)
Gently lift those springs out and keep in safe place before removing shock-absorbing rubber cushion. After this you should see battery compartment is underneath of another white-plastic panel:
On the battery-compartment has an instruction-label that need to be followed after battery is replaced. Pay attention on them.
One side of panel has a latch that holds the battery down. If you look closely by using a magnified loupe you will figure it out how to un-latch: Use flat-screw driver push-pull the latch to the left:
Use plastic tweezer for battery replacing: Pickup the old one out and properly recycle. (Lithium toxic). Insert the new one in carefully, avoid to zap the terminals with other metal parts.
After placed the new battery in its compartment properly. Blow dust out, neither leave the finger-prints on the battery terminals nor the movement. (it contains salt and oil will rust the watch). As usually I used latex gloves:
Check the latch is hooked downmost to the base surely. Return all contact-springs back to the same places where they belong to after put the insulation plastic and rubber cushion back. The assembly-principle is "Last out, First in" (LOFI)
Use a small tip metal tweezer to short (-) and (AC) terminals per instruction before closing the back. Look at the display should see all digital-segments flash up.
Apply Silicone Lubricant on the gasket. This special grease will prevent the water from leaking into the watch, but will not deteriorate the rubber gasket. If you could buy a new gasket it would be perfect, otherwise use the same old one, then it is still working great. Tightly, evenly srew the back-case, but not exceedingly. (the plastic threads may be 'screwed-up')
I put my watch into a bowl of water (for coolant), then bring it under sun-beam for an hour ensure fully charge it, but not burn it. Test synchronous, alarm, light... all functions are working good: