What a Smart Ring Reveals About Wireless Power

Smart ring-class battery current budget over a six-day target

Figure 1. A mid-size smart ring-class battery of 18.5 mAh, spread across a six-day target, gives the entire device an average current budget of about 128 µA. Calculation: 18.5 mAh ÷ 144 h ≈ 0.128 mA = 128 µA

Smart rings are a brutal battery-life test.

A phone carries thousands of milliamp-hours. A smartwatch carries a few hundred. A smart ring carries only tens.

Samsung's Galaxy Ring is a useful reference point. Its battery ranges from 17 mAh to 22.5 mAh, depending on size. Sizes 8 through 11 use an 18.5 mAh cell and are rated for up to 6 days on a single charge.

Spread across six days, that 18.5 mAh gives the entire device an average current budget of about 128 µA.

That budget has to cover everything: sensors, processor, memory, firmware, LEDs, power management, and the wireless link.

So the design question is simple:

How much of that budget should wireless communication be allowed to take?

A smart-ring battery budget

The Ixana Wi-R Power Profiler compares average current and battery life between Bluetooth LE and Wi-R. The currently displayed profiler operating points show a Bluetooth LE profile based on a typical nRF52-class SoC and a Wi-R YR23 profile based on YR23 datasheet data.

Applying those displayed current numbers to an 18.5 mAh smart-ring-class battery gives the following link-only comparison:

Link profile	Profiler average current	Link-only runtime on 18.5 mAh	Profiler energy per bit
Bluetooth LE profile	175 µA	~4.4 days	25.6 nJ/bit
Wi-R YR23 profile	11.6 µA	~66 days	0.392 nJ/bit

BLE versus Wi-R YR23 average current against the smart ring current budget

Figure 2. The selected BLE operating point exceeds the six-day average current budget of an 18.5 mAh smart ring-class battery, while the Wi-R YR23 operating point uses only a small fraction of that budget. Values are from the Ixana Wi-R Power Profiler; the 128 µA budget is calculated as 18.5 mAh ÷ 144 h

This is not a teardown of the Galaxy Ring's actual radio behavior. It is a product-level budget comparison: take a real smart-ring-class battery, then apply the wireless current profiles shown in the Power Profiler.

Over a six-day target, the selected BLE operating point would integrate to about 25.2 mAh of link-related charge. That exceeds the nominal 18.5 mAh capacity of a mid-sized Galaxy Ring battery before the ring has powered a single sensor or processor cycle.

The Wi-R YR23 operating point would draw about 1.7 mAh over the same six days, or roughly 9% of the same battery budget.

Cumulative link-related charge demand over six days for BLE versus Wi-R YR23

Figure 3. Over six days, the selected BLE operating point would draw about 25.2 mAh of link-related demand, exceeding the nominal 18.5 mAh capacity of a mid-size smart ring-class battery. The selected Wi-R YR23 operating point would draw about 1.7 mAh over the same period. Calculations use average current × 144 hours.

Current determines whether the link fits inside the battery. Energy per bit shows the other side of the tradeoff: how much it costs to move data under the selected operating point. In the displayed profiler comparison, Wi-R uses 15.1× lower average current and roughly 65× lower energy per bit than the BLE profile.

Why this matters

For a smart ring, lower wireless power does more than extend battery life. It changes what the product can afford to do.

A lower-power link frees current for more frequent syncs, richer sensing, and less aggressive data buffering. It makes coordination with a phone, watch, earbuds, or glasses cheaper to sustain. It also gives designers more room to spend the reclaimed budget elsewhere: a smaller battery, a thinner form factor, or more capable sensors.

That is the point of the Power Profiler.

It turns wireless power from an abstract spec into a design constraint you can test. Pick a battery. Set the link profile. See whether the communication budget fits the product.

For smart rings, wearable AI devices, medical patches, earbuds, and AR accessories, that question matters more than peak data rate alone.

The best wireless link is not just the one that connects. It is the one that leaves enough battery for the rest of the product.

Try the Ixana Wi-R Power Profiler to compare BLE and Wi-R operating points against the battery budget your device actually has.