Oura’s IPO Filing Puts $84.4 Million on Ring 4 Batteries

Oura’s IPO filing ties an $84.4 million jump in warranty costs to battery failures in some Ring 4 production groups. The Form S-1, sent to the U.S. Securities and Exchange Commission on September 3, 2026, is the first public account of a defect owners had been logging with support for a year.

The filing says Oura replaced affected rings free of charge, including some after the one-year warranty ended, and it still does not name the serial numbers, sizes, or purchase dates in those groups.

The S-1 Puts an $84.4 Million Number on the Complaints

Hardware revenue in fiscal 2025, the year ended September 30, 2025, rose $418.2 million, or 126 percent, after the October 2024 launch of Ring 4. Rings sold went from 1.0 million to 2.3 million, a 131 percent increase. Cost of revenue moved with that volume, and it also moved because the batteries in some of those new rings did not hold up.

The MD&A in the registration statement attributes the $84.4 million increase in warranty expense to elevated reserves on certain Ring 4 battery cohorts. In the risk factors, the company is more direct about what it did next.

Certain cohorts of Oura Ring 4 have exhibited battery performance issues, which has resulted in increased warranty claims and warranty-related costs as we have replaced affected Oura Rings free of charge under our warranty and, in some cases, outside of the warranty period.

Oura Inc., Form S-1, U.S. Securities and Exchange Commission

The cash followed the reserve. Oura’s warranty liability was $17.5 million at the start of fiscal 2025, $98.3 million on September 30, 2025, and $132.3 million on June 30, 2026. Claims paid were $28.8 million in fiscal 2025, then $75.5 million in the nine months through June 30, 2026. Rings sold are counted net of warranty replacements, so those swaps sit on the cost line and never show up as new sales.

THE GROWTH THAT SHARES THE PAGE

• Rings sold: 3.1 million in the nine months through June 30, 2026, up 75 percent from 1.8 million a year earlier.
• Paid members: 5.0 million at June 30, 2026, double the 2.5 million a year earlier.
• Revenue: $1.21 billion in those nine months, up 74 percent from $697.6 million.
• Net income: $60.8 million in those nine months, against $1.6 million a year earlier and $12,000 in fiscal 2025.

Gross margin in that nine-month stretch still widened from 51 percent to 55 percent, which the filing credits to lower warranty rates against earlier hardware groups and to cheaper per-unit manufacturing. Warranty costs in the same window were still $28.6 million higher than the year before. The reserve is no longer exploding at the 2025 pace. The bill is still being paid.

Oura’s Own Warranty Still Calls Batteries a Consumable

The customer-facing warranty, last updated August 18, 2026, covers manufacturing defects under normal use for one year from purchase, or longer where local law requires it. Many countries outside the United States get two years. Certified refurbished rings get 90 days. Extended coverage is an add-on through a third-party plan on U.S. store orders.

The same help page lists batteries as consumable parts, grouped with losses, scratches, dents, and secondhand purchases from unauthorized sellers. That is the written rule owners see when a ring that was sold on a multi-day charge starts dying overnight.

WHAT THE LIMITED WARRANTY DOES NOT COVER

• Lost or stolen products: Theft and loss are outside the limited warranty.
• Normal wear: Scratches and dents from everyday handling are excluded.
• Batteries: Consumable parts, including batteries, are named as uncovered.
• Unauthorized resale: Secondhand rings bought from unauthorized sellers are excluded.

The IPO filing describes a different practice for Ring 4. Oura replaced affected units under warranty and, in some cases, after that period had ended. The help page still tells people to start with Finn, the virtual assistant, and to send an order number, a description, photos, and the model and size. Most approved replacements arrive in 1 to 2 weeks, in the same model and size. The original ring may be disabled once the new one is set up.

The S-1 adds a limit that the help page does not. Oura says it may not replace damaged or faulty products in the future at the same level, or on the same terms, as it has replaced Ring 4. The generous swaps are described as history, not as a standing promise.

How Long the Ring 4 Was Supposed to Last

The live store still sells Ring 4, from $349 for silver, and still says a charge lasts 5 to 8 days. Membership after the included first month is $5.99 a month or $69.99 a year in the United States. The ring is fully titanium, 7.90 mm wide and 2.88 mm thick, water resistant to 100 meters, and sized 4 to 15.

Oura’s own battery article is more precise than the marketing line. The 5 to 8 day range comes from tested new, unworn Ring 4 devices in sizes 8 to 10, worn all day, with activity heart rate on for one hour, blood oxygen sensing off, and eight hours of sleep. Charge time is 20 to 80 minutes. Blood oxygen sensing can cut as much as two days. Heavier activity tracking can cut as much as two days. Smaller rings carry smaller batteries.

STATED BATTERY LIFE BY MODEL

Those Ring 4 figures were measured on new hardware. The filing now says some production groups never lived that life in the field. Owners who took the 5 to 8 day claim at face value were left to decide whether a two-day ring was their settings, their size, ordinary lithium aging, or one of the unnamed cohorts.

Replacements Without a Recall List

Oura has not published serial numbers, ring sizes, or purchase-date windows for the bad groups. The S-1’s language is “certain cohorts.” Owners who want to know if they are in one still have to open a support ticket and hope the logs look bad enough.

FROM LAUNCH TO THE FILING

1. October 2024: Oura Ring 4 ships, fully titanium, with a 5 to 8 day battery claim.
2. Fiscal 2025: Warranty expense rises $84.4 million on battery performance issues in some Ring 4 groups; claims paid reach $28.8 million.
3. June 4, 2026: Oura Ring 5 launches. The filing says the company is watching that generation closely.
4. June 30, 2026: Warranty liability stands at $132.3 million after $75.5 million of claims in nine months.
5. September 3, 2026: The Form S-1 makes the Ring 4 battery problem a matter of public record.

The company says the 2025 spike traces to earlier design, manufacturing, and supplier factors, and that it has added testing, quality work, and supply-chain checks. It also says it deployed AI diagnostics and support tools to process the warranty queue. That is a software funnel for a hardware miss. It is not a list of affected rings.

Replacement units are not a clean ending. Owners who already took one swap have watched the new ring fade toward daily charging near the one-year mark, and some are on a third unit. Support will sometimes ship after the written warranty if battery logs look failed. A confirmed fault can still stall when the company will not send a replacement to the country where it sold the ring. The installed base is doing the sorting that a serial list would have done in a week.

Five Million Paid Members Need a Working Ring

Membership revenue in the nine months through June 30, 2026 rose $131.7 million, or 121 percent, to $240.5 million, about 20 percent of total revenue. Hardware still supplies the rest; hardware revenue in that stretch rose $385.3 million, or 65 percent. In the third quarter of fiscal 2026, paid members wore the ring a median of about 23 hours a day. The product is sold as all-day kit, and the subscription is sold on the back of that kit.

The S-1 states the link in one clause. Access to membership depends on the ring keeping up, so a dead battery is not only a hardware return. It is a $69.99-a-year relationship that cannot collect sleep, readiness, or activity if the band on the finger is on a charger every night. That is why the company paid for swaps after the one-year window on some Ring 4 units. A silent ring does not stay a paying member for long.

Oura’s own risk factor list puts actual or perceived defects, including battery performance, next to warranty claims, replacements or recalls, reputational harm, and litigation. It also flags a limited set of contract manufacturers and suppliers. The Ring 4 miss is already in the warranty line. The open question for anyone reading the S-1 as an equity story is whether the next generation repeats it.

Ring 5 Already Ships With a Rebuilt Battery

Oura did not wait for the IPO filing to change the power system. Ring 5, which the company called its smallest smart ring, started shipping on June 4, 2026. Official materials say the battery system was rebuilt, a chemical and mechanical redesign with firmware aimed at longevity, even though the ring is 40 percent smaller than Ring 4. Stated life is 6 to 9 days. Sizes run 6 to 13, a narrower range than Ring 4’s 4 to 15.

The S-1, written after that launch, still warns that current or future generations could hit similar quality problems and that warranty costs can keep swinging margins in the near term. The company treats the Ring 4 spike as backward-looking. It does not treat battery risk as closed. Ring 4 remains on the store beside the new model, with the same 5 to 8 day line that the filing has now qualified in a different document, for a different audience.

What Ring 4 Owners Can Do Now

There is still no public batch list, so the path is the support queue the company already built to handle the defect. Finn can run diagnostics and, if the logs qualify, open a replacement. A member-care agent can do the same by chat or email. The filing’s record of out-of-warranty swaps is useful context for anyone whose one-year window has closed, and it is not a guarantee of the same outcome.

IF THE RING IS DYING EARLY

• Capture the drain: Note days per charge, size, and whether blood oxygen sensing is on, then screenshot battery history in the app.
• Open a ticket: Have the order number, model, size, and photos ready; replacements ship in the same model and size.
• Ask about logs: Oura has used battery logs to approve swaps, including some after the written one-year term.
• Watch the original: A replaced ring may be disabled and should not be sold or given away.

The S-1 that named the defect also said Oura may not replace faulty rings in the future on the terms it used for Ring 4. For anyone whose band is already down to a nightly charge, that line is the deadline hiding in the growth story.