Ultrahuman wants you to swap your smart ring battery in seconds

Ultrahuman is exploring a smart ring with a removable battery . The idea is similar to a detachable-battery design we previously spotted from Oura, but Ultrahuman adds an interesting twist: a small backup battery that keeps the ring running while the main one is removed.

A newly published US patent application from the company describes a smart ring built around that idea. It was filed in February 2025 and published on August 20, 2026 as US 2026/0246054 A1.

Anyone who has owned a smart ring for a few years will understand the problem. These devices are designed for continuous wear, but their batteries are usually permanently sealed inside. Once capacity drops significantly, replacing the battery is generally not practical and the entire ring can end up needing replacement.

Ultrahuman’s answer is to make the battery itself part of a removable section of the ring.

Swap the battery without stopping the ring

The drawings show a main ring body containing the sensors and electronics, with a curved battery section that attaches to it. Ultrahuman lists several possible ways of securing the two pieces, including magnets, a sliding lock and a snap-fit mechanism.

Electrical contacts automatically connect the battery module to the rest of the ring once it is attached. The patent mentions spring-loaded pins, pogo pins and magnetic contacts as possible approaches.

But the clever part is what happens when you take that battery out.

Ultrahuman proposes putting a smaller “residual battery” inside the main ring body. When the removable battery is detached, this smaller battery temporarily powers the sensors and electronics. Once a charged module is attached, a switching mechanism moves power back to the larger battery.

In theory, you could keep a second battery module charged and swap it in within seconds. The ring would continue recording while you do it, rather than spending an hour or two sitting on a charger. That is particularly interesting for sleep and recovery tracking, where missing chunks of data can affect the following day’s scores.

Oura has been thinking along similar lines

This isn’t the first removable smart ring battery design we’ve come across.

Earlier this year, we covered an Oura patent for a smart ring with a detachable battery section. Oura’s approach also separates the battery housing from the sensor-equipped portion of the ring, allowing the power module to be removed and replaced.

The two ideas attack much the same problem, although Ultrahuman’s residual battery makes its version particularly interesting. Instead of simply making the main battery replaceable, the filing is designed around keeping the ring operational during the swap.

That could also make charging work quite differently. Rather than charging the whole ring every few days, you could potentially charge individual battery modules separately and rotate them.

Battery ageing may be the bigger benefit

Convenience is only half the story. Replaceable batteries could substantially extend the useful life of smart rings.

I found battery performance pretty solid when I tested the Ultrahuman Ring Air, with the ring typically losing around 15 to 20% charge per day. But lithium batteries inevitably degrade with repeated charging cycles, regardless of how well they perform when new.

Ultrahuman explicitly talks about this in the filing. Instead of throwing away an otherwise functional ring when its battery deteriorates, the owner could simply replace the battery module. The company also suggests different battery capacities could eventually be offered, opening the possibility of choosing between a lighter module and one designed for longer runtime.

There is even an outer shell in some of the drawings that fits over the ring and removable battery section. This could be made from silicone, metal or a combination of materials, helping disguise the modular construction and making the finished device look more like a conventional ring.

None of this means Ultrahuman is about to launch such a product. Patent filings regularly cover ideas that never make it into commercial hardware, and making a removable section durable, waterproof and comfortable enough for continuous wear would bring its own engineering headaches.

But this is now at least the second major smart ring company we’ve seen exploring replaceable batteries. That makes the broader idea more interesting than any one patent.