The physics of a smart ring battery
A typical DL110-class ring has a lithium-polymer battery somewhere between 17 and 22 mAh. For reference, a cheap TWS earbud has ~40 mAh, and an iPhone has ~3,000 mAh. Your ring is running on about 0.6% of an iPhone battery.
To get anywhere near a week of use, the ring has to spend 99% of its time in deep sleep mode, sipping microamps. Every time it wakes up to measure or sync, it burns battery. The advertised battery life assumes minimal measurements and ideal conditions — which is rarely what you actually get.
What drains the battery fastest
1. Continuous heart rate monitoring
If the ring is set to measure HR every 1 minute instead of every 5, battery life gets cut roughly in half. The green LED plus the ADC sampling are the single most expensive operations the ring performs.
Fix: in your ring app, set HR measurement interval to 5 minutes or longer. Ringlo defaults to a balanced interval; the stock apps often default to continuous.
2. Continuous SpO2 monitoring
SpO2 is even more expensive than HR — it uses red + IR LEDs simultaneously, and those are higher current than green. Continuous SpO2 can halve battery life on its own.
Fix: turn off continuous SpO2. On-demand readings and overnight sampling give you 95% of the value at 5% of the battery cost.
3. Staying connected to the phone constantly
A persistent BLE connection (even idle) consumes power because the ring has to listen for phone commands and send keepalives every few seconds. The stock SmartHealth app aggressively maintains connection because it's bad at background sync.
Fix: Ringlo uses opportunistic sync — connect → sync → disconnect. Much easier on the battery over a 24-hour period.
4. Cold weather
Lithium-polymer capacity drops sharply below about 10°C (50°F). In winter, you can lose 20-40% of apparent battery life even without changing your usage.
Fix: there's no software fix. This is physics. Wearing the ring keeps it at body temp; taking it off and leaving it on a cold dresser lets it discharge faster.
5. Old firmware / firmware bugs
Early DL110 firmware had a known bug where the ring would stay in high-power mode after certain BLE disconnect sequences. If you've never updated firmware and the ring is older, you may be stuck with a buggier version.
Fix: firmware updates are done through the stock app (SmartHealth / HBand). Ringlo doesn't currently do firmware updates — we'll be adding this.
6. The battery is genuinely dying
Li-po batteries of this size typically lose meaningful capacity after 200-400 full charge cycles. If your ring is 18 months old and charging daily, you've used up a third to half of its useful battery life.
Fix: at $30, these rings are mostly disposable. Replace it when you get sick of charging daily.
Realistic expectations by usage pattern
| Usage | Expected battery life |
|---|---|
| Sleep tracking + 1 manual HR check/day | 5-7 days |
| Sleep + HR every 5 min, SpO2 overnight | 3-5 days |
| Sleep + continuous HR + continuous SpO2 | 1.5-2 days |
| Above + live workout tracking | Closer to 24 hours |
How to extend battery life without losing features
- Use Ringlo's default monitoring intervals. They're tuned for balance between data quality and battery life.
- Skip continuous SpO2. Overnight sampling + on-demand readings covers you.
- Don't leave the ring on the charger overnight. Lithium batteries don't like being held at 100% for 8 hours. A quick 45-min charge every other day is healthier than overnight charging every night.
- Charge between 30% and 90%. The edges of the charge curve are where battery wear accelerates. Both extremes hurt cycle life.
- Keep the ring warm. Wearing it most of the day helps capacity in cold weather.
The Ringlo advantage
- Opportunistic BLE sync instead of constant connection — saves hours of idle current per day.
- Smart HR intervals that dynamically increase during activity and relax at rest.
- Low battery alerts at 20% so you're never surprised mid-day.
- Charge completion notifications so you're not overcharging.
Tired of your ring dying in 2 days? Try Ringlo — 14-day free trial, no card required.