1. Introduction
This manual provides essential instructions for the proper use and maintenance of your G-Shock Casio GBD800UC-3 Digital Power Trainer Watch. This timepiece is engineered for durability and features advanced functions for fitness tracking and daily utility, including Bluetooth connectivity for smartphone integration. Please read this manual thoroughly to ensure optimal performance and longevity of your watch.

Figure 1.1: Front view of the G-Shock GBD800UC-3 watch. The display shows time, day, and date, with indicators for Bluetooth and step tracking. Buttons are labeled ADJUST, SET, MODE, SELECT, LIGHT, CONNECT, STOP, START, and LAP/RESET.
2. Setup
2.1 Initial Time Setting
Your watch is pre-set at the factory. For initial setup or after a battery change, you may need to adjust the time.
- Press and hold the ADJUST button until the city code starts to flash.
- Use the MODE and SELECT buttons to navigate through settings.
- Use the LIGHT and START buttons to change values.
- Press ADJUST again to exit the setting mode.
2.2 Connecting to the G-Shock Connected App
The GBD800UC-3 watch can link with the G-Shock Connected app on your smartphone (iOS and Android compatible) via Bluetooth for enhanced functionality.
- Download the "G-Shock Connected" app from your smartphone's app store.
- Enable Bluetooth on your smartphone.
- On the watch, press and hold the CONNECT button (usually the lower right button) until the Bluetooth indicator flashes.
- Follow the instructions within the G-Shock Connected app to pair your watch.
- Once paired, the watch will automatically adjust time and date, and enable data transfer for fitness tracking.
3. Operating the Watch
3.1 Mode Navigation
Press the MODE button to cycle through the different watch modes:
- Timekeeping Mode
- Step Tracker Mode
- Stopwatch Mode
- Countdown Timer Mode
- Alarm Mode
- World Time Mode
3.2 Step Tracker
The built-in 3-axis accelerometer tracks your daily step count.
- In Step Tracker Mode, the display shows your current step count.
- Data can be synced with the G-Shock Connected app to view step logs, calculate calories burned, and set daily step targets.
3.3 Stopwatch
The stopwatch measures elapsed time, split times, and two finishes.
- Enter Stopwatch Mode using the MODE button.
- Press START to begin timing.
- Press STOP to pause/resume.
- Press LAP/RESET to record a lap time or reset the stopwatch when stopped.
- Up to 200 lap records can be stored and viewed via the app.
3.4 Countdown Timer
Set a countdown from 1 second up to 24 hours.
- Enter Countdown Timer Mode.
- Press and hold ADJUST to enter setting mode.
- Use MODE and SELECT to choose the setting (hours, minutes, seconds).
- Use LIGHT and START to change values.
- Press ADJUST to confirm and exit setting mode.
- Press START to begin the countdown.
- The watch supports Multi-Timer functionality via the app, allowing up to 20 timer combinations of five timers each.
3.5 Alarms
The watch features 5 daily alarms.
- Enter Alarm Mode.
- Use SELECT to cycle through alarms (AL1 to AL5) and the hourly time signal (SIG).
- To set an alarm, press and hold ADJUST.
- Use LIGHT and START to set the alarm time.
- Press ADJUST to confirm.
- Press START to toggle the alarm ON/OFF.
3.6 LED Backlight
Press the LIGHT button to illuminate the display for easy reading in low-light conditions.
4. Maintenance
4.1 Cleaning
The watch is designed to be washable. To clean, wipe with a soft, damp cloth. For stubborn dirt, a mild soap solution can be used, followed by rinsing with fresh water. Ensure all buttons are pressed firmly to prevent water ingress during cleaning. Avoid harsh chemicals or abrasive materials.
4.2 Battery Replacement
The watch uses a Lithium Metal battery with an approximate average life of 3 years. When the battery runs low, the display may dim or certain functions may cease to operate. Battery replacement should be performed by a qualified technician to maintain the watch's water resistance and ensure proper function.
4.3 Water Resistance
The GBD800UC-3 is water resistant to 200 meters (20 BAR). This means it is suitable for showering, swimming, and diving.
- Do not operate buttons while the watch is submerged in water.
- Avoid exposing the watch to extreme temperature changes, such as moving from a hot sauna to cold water, as this can affect seals.
- After exposure to saltwater, rinse the watch thoroughly with fresh water and wipe dry.
5. Troubleshooting
- Watch not connecting to app: Ensure Bluetooth is enabled on your smartphone and the watch. Make sure the G-Shock Connected app is updated to the latest version. Try restarting both your phone and the watch. If issues persist, unpair and re-pair the watch through the app settings.
- Inaccurate step count: The accelerometer's accuracy can be affected by arm movements not associated with walking (e.g., driving, typing). Ensure the watch is worn securely on your wrist. Calibrate the step tracker through the G-Shock Connected app if available.
- Display is dim or blank: This may indicate a low battery. Refer to Section 4.2 for battery replacement information. If the issue persists after battery replacement, contact customer support.
- Time is incorrect: Ensure the watch is successfully paired with the G-Shock Connected app, as it automatically adjusts time. If not connected, manually adjust the time as described in Section 2.1.
For further assistance, refer to the comprehensive help section within the G-Shock Connected app or visit the official Casio G-Shock support website.
6. Specifications
| Feature | Detail |
|---|---|
| Model Number | GBD800UC-3 |
| Brand | G-Shock (Casio) |
| Display Type | Digital |
| Case Material | Resin |
| Band Material | Resin |
| Color | Green |
| Water Resistance | 200 Meters (20 BAR) |
| Connectivity | Bluetooth |
| Sensors | 3-axis Accelerometer (Step Tracker) |
| Battery Type | Lithium Metal |
| Battery Life (Approx.) | 3 years |
| Dimensions (Item) | 2.12 x 1.91 x 0.61 inches |
| Screen Size | 48.6 Millimeters |
| Compatible Devices | Smartphones (iOS and Android) |
7. Warranty and Support
Your G-Shock GBD800UC-3 watch is covered by a manufacturer's warranty. For specific warranty terms and conditions, please refer to the warranty card included with your purchase or visit the official Casio G-Shock website.
For technical support, service, or inquiries regarding your watch, please contact Casio customer service or visit their official support portal.
- Online Support: www.casio.com/us/support/
- Product Page: www.gshock.com