"What kind of battery is inside?

Index 01 uses silver-oxide batteries.

Why can’t it be recharged?

We considered this but decided not to for several reasons:

You’d probably lose the charger before the battery runs out! Adding charge circuitry and including a charger would make the product larger and more expensive. You send it back to us to recycle. Wait, it’s single use?

Yes. We know this sounds a bit odd, but in this particular circumstance we believe it’s the best solution to the given set of constraints. Other smart rings like Oura cost $250+ and need to be charged every few days. We didn’t want to build a device like that. Before the battery runs out, the Pebble app notifies and asks if you’d like to order another ring."

Uhhh... Huh... Ok. Welp, that's a nope from me then.

The choice release a non-rechargeable/non-serviceable product feels like something that shouldn't be dismissed with "...lasts for years..." and "...you''d probably lose the charger..." This language feels patronizing to me. Even the "...[it] asks if you’d like to order another ring," begs the question: at what cost?? 99$, I presume.

The target market might not be exclusively other engineers and tinkerers, but as an engineer and tinkerer, I'm eager for more details about the testing, verification, construction, etc., of such a solution.

On the other hand, cool!

> No charging: The battery lasts for up to years of average use. After the end of its life, send your ring back to us for recycling.

I shared your concerns but I read this bit and I think it's all pretty reasonable if you ask me. They're open and upfront about it, and you can very quickly choose not to buy one.

Who's recycling their Oura battery anyway? Probably nobody.

So in a way it is similar to Subscription ?

> the Pebble app notifies and asks if you’d like to order another ring

This comes across much more dystopian than I imagine the author intended.