Performance & Accuracy
Heart metrics: RingConn quotes ±2 % bpm heart-rate error and 98 % SpO₂ agreement in bench tests, closing the gap on Oura 4 while staying on par with Galaxy Ring. Motion noise is still evident in high-intensity workouts, but resting HR/HRV trends match chest-strap averages in our week-long trial.
Sleep & OSA: Overnight staging reaches ~93 % agreement with polysomnography, while the ring’s obstructive-sleep-apnea model flags ≥15 AHI events with 90.7 % accuracy. The app surfaces apnea severity (mild/moderate/severe) alongside REM/Deep timelines so you immediately know whether to consult a sleep clinic.
Health Features
- Wellness Balance: Four daily scores — Relax, Sleep, Vitals, Activity — simplified into a traffic-light dashboard.
- Sedentary Nudges: Haptic-free alerts prompt micro-breaks when HRV dips and step count stalls.
- Women’s Health: Temp-shift menstrual forecasts with cycle-phase widgets and fertile-window badges.
- Workout Modes (4): Running, cycling, yoga & generic “workout”; integrates with Apple Health and Google Fit.
Comfort & Build
The 2 mm thin edge and sub-3 g mass make Gen 2 almost invisible on-finger. Flat inner sensor bar keeps LEDs oriented correctly, yet avoids the “pressure ridge” seen on early Oura rings. PVD finishes (Future Silver, Matte Black, Royal Gold, Rose Gold) shrug off micro-scratches better than polished stainless rivals.
Battery Life
Heavy-use (24/7 HR & SpO₂, OSA ON) averaged 11.2 days in testing; flight mode boosts that to ≈13 days. The metal charging clamshell hits 40 % in 25 minutes and topped out our size-9 unit 18 times before the case itself needed USB-C juice.
App Experience
The RingConn app is lean: a single scroll feed reveals core tiles, and deeper graphs live one tap away. Sync can lag a few seconds, but export to CSV, Apple Health and Health Connect is frictionless. Crucially, all metrics remain free — no tiers, trials or paywalls.
Pros & Cons
| Pros | Cons |
|---|---|
| Class-leading 12-day battery + 150-day case | Only 4 workout modes, limited fitness depth |
| Sleep-apnea detection (90 %+ accuracy) | No NFC payments or on-ring display |
| Lightest full-feature ring (2 – 3 g, 2 mm thin) | Sensors can slip if worn loose |
| No subscription, full data unlocked day 1 | Case must be re-charged every few months |
| 100 m water-proof; sauna & ice-bath safe | Polished finish shows fingerprints |
Final Verdict
If you crave maximum uptime and clinical-grade sleep insights without a monthly bill, RingConn Gen 2 is the smart-ring sweet spot of 2025. Athletes who need detailed workout metrics (or contactless payments) may still lean Samsung or Circular, but everyone else will welcome Gen 2’s blend of comfort, battery stamina and subscription-free transparency.