Oura has confirmed that some Oura Ring 4 rings have a battery fault, and the admission is in a prospectus written for investors. The filing, first lodged with the US Securities and Exchange Commission on September 3 and amended on September 21 ahead of a Nasdaq listing under the ticker OURA, says “certain cohorts of Oura Ring 4 have exhibited battery performance issues”. Oura adds that it has replaced affected rings free of charge “and, in some cases, outside of the warranty period.” That last clause is the one to remember if your Ring 4 battery no longer lasts the week.
What the filing says about the batteries
The wording is brief, and Oura doesn’t name the batches, the months they were built, the symptom or the number of rings involved. A cohort here means a group of rings made in the same period, so two Ring 4s bought from the same store can behave differently.
The battery problem shows up in three places in the filing. One is the risk section quoted above. In the explanation of costs, Oura says reserves for those same Ring 4 batteries drove an $84.4 million rise in warranty expense in the year ended September 30, 2025. It comes up a third time to explain lower margins in the nine months ended June 30, 2026, next to a line about the AI diagnostic tools Oura now uses to process these claims.
The filing calls them performance issues. It describes no overheating or swelling, and it mentions no recall.
Oura’s support pages say something else
Three Oura help documents, all revised in the past six weeks, don’t mention it. The warranty FAQ, updated on August 18, lists “consumable parts, including batteries” among the things the limited warranty doesn’t cover. The Oura Ring 4 battery life article was updated on September 21, the day of the amended filing. It still ends by saying that “based on early usage of Oura Ring 4, these controlled environment estimates remain accurate.” The Known Issues list, revised on September 28, has entries for missing sleep data and slow syncing but none for the battery.
An owner reading the help site would take a fading battery for normal wear. The prospectus tells investors that some of it is a fault Oura pays to fix.
Both can be true for different rings, because every lithium cell loses capacity. To tell which applies to yours, check how far its battery life has drifted from Oura’s rating.
The warranty bill, divided by rings sold
Each time Oura sells a ring, it sets money aside for the warranty claims it expects. The prospectus gives that provision and the number of rings sold, so the two can be divided.
| Period | Warranty provision | Rings sold | Set aside per ring |
|---|---|---|---|
| Year to 30 Sep 2024 | $12.6 million | 1.0 million | about $13 |
| Year to 30 Sep 2025 | $103.3 million | 2.3 million | about $45 |
| Nine months to 30 Jun 2026 | $113.2 million | 3.1 million | about $37 |
The division is ours, and it’s rough. Oura counts rings sold after returns and warranty replacements, and the provision covers every model and every kind of defect. Still, the Ring 4 went on sale on October 15, 2024, two weeks into the year in which the amount per ring more than tripled.
The claims Oura paid out grew from $9.7 million to $28.8 million in that year. In the following nine months they reached $75.5 million. On June 30, Oura still held $132.3 million for claims it expects but hasn’t paid yet, the largest balance anywhere in the filing.
Is your ring one of them?
Oura rates the Ring 4 at five to eight days on a charge. That rating comes from new rings in sizes 8 to 10, with blood oxygen sensing off, eight hours of sleep a night and an hour of detected activity a day. The same help page says blood oxygen sensing can take up to two days off, and two or three hours of daily activity tracking up to two more. Smaller rings hold smaller batteries.
So a small ring with every sensor on can get down to about three days and still be within what Oura describes. Rule that out first. Switch blood oxygen sensing off for a few nights, update the app and the ring firmware, charge to full and note how long it lasts.
If the ring still falls well short of five days with those settings, it’s doing worse than Oura promises for a new Ring 4, and you have a case to take to support. Oura hasn’t published the threshold it uses to call a battery faulty, and a ring from late 2024 will have lost some capacity through ordinary use.
Asking Oura for a replacement
Claims start with Finn, the virtual assistant in the app and on the support site. Finn can approve some replacements on its own and hands the rest to a person by chat or email. The warranty page asks for your order number, a description of the problem and what you’ve tried, and photos or screenshots. It also wants the ring’s model and size, which you’ll find on the My Devices page in the app.
Screenshots of the battery level on several days in a row make the strongest case. If your ring is past its first year, say so, and quote Oura’s statement to investors that it has replaced affected Ring 4s outside the warranty period. The filing doesn’t promise that to everyone, and Oura hasn’t said how it decides.
Outside the US, check the legal minimum before you accept “out of warranty” as an answer. In the EU, the seller is liable for faults for at least two years, and Oura’s own warranty page says its team applies whatever coverage your country requires.
Sync the ring before you send anything. Only data already synced to your account carries over, and the old ring may be disabled once a replacement is approved. The new ring will be the same model and size, and it may be refurbished. Its coverage runs for the rest of your original warranty or 90 days, whichever is longer. The warranty page asks owners to recycle the old ring, so don’t sell it or give it away.
Buying a ring this fall
The Ring 5 arrived on June 4, 2026 with a rating of six to nine days, and the filing says only that Oura is monitoring its performance closely. Like the Ring 4, it has a sealed battery that cannot be replaced, which the Oura Ring 5 review weighs against the price and the membership. Whichever model you choose, keep the receipt and the purchase date where you can find them in two years.
Check again if Oura lists the affected batches or adds the battery to its Known Issues page. Until then, the prospectus is the only place Oura has admitted the fault.
