Most Wear OS watches ask you to charge every other night. The Watch 4 is built around the opposite decision: a 646mAh battery, roughly double what a typical Wear OS watch carries, paired with a second low-power chip that handles the watch when the main processor is asleep. OnePlus rates it at five days in smart mode and sixteen in power saver, which is what makes it worth considering against the obvious alternatives.
Key features
Two chips, and the battery life that follows
A Snapdragon W5 handles Wear OS, while a BES 2800 takes over for everyday timekeeping, notifications and sensor logging. The 646mAh cell is large for the category, and OnePlus quotes three days even under heavy use. Charging is 7.5W over a magnetic dock and takes about 75 minutes from empty.
Titanium case, sapphire glass, and a genuine set of ratings
The case is titanium with a sapphire crystal over the display, and the durability ratings are unusually complete: 5ATM, IP69 and IP68, plus MIL-STD-810H. IP69 in particular covers high-pressure hot water jets, which is not something most watches at any price claim.
An LTPO OLED that pushes to 3,000 nits
The 466 x 466 flexible LTPO OLED runs at 600 nits by default and lifts to 1,500 nits in bright light, with a 3,000-nit peak that the watch triggers automatically in its own workout modes. LTPO matters here because it lets the refresh rate drop when the screen is idle, which is part of how the battery figure holds up.
Dual-band GPS and 100+ workout modes
Positioning is dual-band L1 + L5 across BeiDou, GPS, Galileo, GLONASS and QZSS. There are over 100 workout modes with six that start on their own — running, walking, cycling, swimming, rowing machine and elliptical. Bluetooth calling works through the built-in speaker and microphone, and NFC supports Google Wallet.
Specifications
| Specification | Detail |
|---|---|
| Case size and weight | 47.4 x 47.4 x 11.0 mm, about 43 g without strap |
| Display | LTPO OLED, 466 x 466, 310 PPI, sapphire crystal, up to 3,000 nits peak |
| Processors | Qualcomm Snapdragon W5 with BES 2800 co-processor |
| Memory and storage | 2 GB RAM, 32 GB storage |
| Battery | 646 mAh typical; 16 days power saver, 5 days smart mode, 3 days heavy use; 7.5W magnetic dock, about 75 minutes to full |
| Sensors | Optical heart rate, SpO2 with low-oxygen alerts, wrist temperature, barometer, gyroscope, accelerometer, geomagnetic, ambient light |
| Positioning | Dual-band GNSS, L1 + L5 |
| Water and dust | 5ATM, IP69, IP68, MIL-STD-810H |
| Connectivity | Bluetooth 5.2, Wi-Fi 2.4 + 5 GHz, NFC with Google Wallet, speaker and microphone. No eSIM or LTE |
| Platform | OxygenOS Watch 8 on Wear OS 6.0, with Gemini and Google Assistant |
| Phone requirement | Android 9.0 or above with Google Mobile Services 23.45.23 or later. iOS is not supported |
| Wrist size | 140-210 mm |
| Workout modes | Over 100, six auto-detected |
| Stock type | International version |
Who it's for
- Android users who want Wear OS and Google Play apps without charging the watch nightly.
- Anyone who has broken a watch before and wants titanium, sapphire and a full set of durability ratings.
- Runners and cyclists who need dual-band GPS in dense urban terrain.
- Not for iPhone users, and not for anyone who needs the watch to work without a phone — there is no eSIM version.
Warranty and delivery
This is an international version: a brand-new unit brought in from an overseas market, with the same hardware and software as local stock, but warranty running through us rather than OnePlus Hong Kong. Cover is our 10-day exchange for units that fail. Every unit is 100% brand new and you can book a fitting at our Kwun Tong shop before ordering. Full terms are on the warranty policy page, and our parallel import versus licensed goods guide explains the difference in full.
Non-TV items ship by SF Express freight-collect, with the customer paying the shipping fee, or collect free at the Kwun Tong shop between 11:00 and 19:00. Details are on the shipping policy page.
Frequently asked questions
Does the ECG feature work in Hong Kong?
Treat it as unavailable. The hardware is there as part of the 60-second health check, but OnePlus states that ECG activation depends on medical-device registration in each market, and Hong Kong is not on the list of registered regions it publishes. Do not buy this watch for ECG.
Can I pair it with an iPhone?
No. The Watch 4 runs Wear OS and requires an Android phone with Google Mobile Services. If you carry an iPhone, the OnePlus Watch Lite is the model in this range that supports iOS.
Is there an LTE version?
No. The OnePlus specification sheet lists eSIM and cellular as unsupported, so the watch always needs your phone nearby for data.