One of the major reasons for choosing a smart ring over a smartwatch is battery life.
Most smart rings last between 6 and 15 days on a charge, while most smartwatches with a bright screen last one to two days.
A smartwatch has to power a display, GPS, and a full operating system, which is hungry for power. The large batteries required mean the form factor can be chunky too. The Apple Watch, which launched in 38 mm and 42 mm sizes, has now grown to 46 mm .
For those who want to track sleep with their wearable, smartwatches can be uncomfortable, and most require charging every day.
In this guide, we explain how current rings and watches compare on battery life, where the difference comes from, and when a watch is still the better choice.
Highlights
- Smart rings: up to 15 days.
- Apple Watch Series 12: up to 24 hours. Ultra 4: up to 50 hours.
- A smart ring battery is around 20 mAh and a smartwatch battery is 300 to 450 mAh, but the watch runs out first because its screen and GPS use far more power.
- Some watches, such as Garmin’s Venu 4, last 10 days or more.
Battery life compared
| Device | Type | Rated battery |
|---|---|---|
| Ultrahuman Ring PRO | Ring | Up to 15 days (Chill), about 12 (Turbo) |
| RingConn Gen 3 | Ring | Up to 14 days |
| Oura Ring 5 | Ring | 6 to 9 days |
| Samsung Galaxy Ring | Ring | Up to 6 or 7 days, by size |
| Garmin Venu 4 | Watch | 10 to 12 days (smartwatch mode) |
| Galaxy Watch 9 | Watch | 30 to 40 hours |
| Pixel Watch 5 | Watch | 30 to 40 hours with always-on display |
| Apple Watch Ultra 4 | Watch | Up to 50 hours |
| Apple Watch Series 12 | Watch | Up to 24 hours |
Why smart rings last longer
There is no screen. The display is the biggest power draw on most smartwatches, and an always-on display uses power even when you are not looking at it.
There is no GPS. GPS is one of the biggest power draws on any watch. Running it cuts the Garmin Venu 4 from 10 days to 15 hours .
It does one job. A ring takes sensor readings and stores them. A watch also runs apps, shows notifications and keeps a phone connection all day.
When a smartwatch is the better choice
You want GPS for runs and rides without carrying your phone. A ring cannot map a route.
You want to see your data on your wrist, or answer messages and calls without picking up your phone.
You want both, which is common. Many people wear a watch for training during the day and a ring around the clock for sleep and recovery, since the ring rarely needs to come off.
Frequently asked questions
Which lasts longer, a smart ring or a smartwatch?
A smart ring, in almost every case. Most rings last 6 to 15 days, and most smartwatches with a full-color screen last 1 to 2 days. A few low-power watches, such as the Garmin Venu 4, last 10 days or more.
Which smartwatch has the longest battery life?
Of the watches compared here, the Garmin Venu 4, at up to 12 days in smartwatch mode on the 45 mm model.
Is a smart ring better than a smartwatch for sleep tracking?
For battery, yes, since you do not need to take it off to charge each night.
Which smart ring has the longest battery life?
The Ultrahuman Ring PRO is rated at up to 15 days. See best long battery life smart ring for five rings compared.
References
- Apple. Apple Watch battery. apple.com
- Apple. Apple Watch Series 12 technical specifications. apple.com
- Garmin. Venu 4 owner’s manual: battery information. garmin.com
- Samsung. Charge your Galaxy Ring. samsung.com
- Oura. Battery life and charging. support.ouraring.com
- RingConn. RingConn Gen 3. ringconn.com
- Ultrahuman Ring Pro: 15-day battery, AI, no subscription. the5krunner, 6 May 2026. the5krunner.com
- Samsung Galaxy Watch9 44mm. T-Mobile. t-mobile.com
- Google Pixel Watch 5 brings faster hardware and built-in Gemini smarts. ProPakistani, 13 Aug 2026. propakistani.pk
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