G SHOCK番CASIO廠更換電池

If you are a DIYer who likes to open up just anything, then read the manual, take #1's advice, and replace the battery yourself. Because when done properly, it can be indeed much cheaper.
However, if you fear that something might go wrong during such battery replacement, then always go back to Javys at 尖吵咀 or 上環 for the job. (I have once had my Data Bank's battery replaced by some unskilled third party but during the process some parts inside got loose. I ended up paying another $40 for the fix)
Price may vary depending on model, starting from $35 (could be higher, I didn't check the updates). Some sensor-based timepieces (Protrek, Sea Pathfinder, G-shock Riseman etc.) may have TWO batteries installed, so the cost will be higher.
The other thing about 原廠更換電池 is that the technician always checks the o-rings etc.to ensure the casing is water-tight after battery replacement.
Also note that any solar-powered rechargable model MUST have the battery replaced at Javys. Price of these batteries may be higher, depending on type.

我果隻係 Sea Pathfinder, 試過返原廠換電收一百大元

換電池唔洗去原廠la....一定貴....G SHOCK去街邊or賣雜錶有電池賣個d就ok la我自己都係咁