The best products are engineered at the mercy of design limitations and clever ways to utilize components and materials in the best way possible.

The Index 01 could be thinner, lighter, safer and wirelessly rechargeable with a rechargeable LFP cell.

So in this instance, we can have everything.

It should still be sustainable in other ways. It matters.

And there are easy ways to address this in the Index 01.

4.7g multiplied by how many per year or per two years? 🙂

The manufacturing of all the material, components etc. matters too.

It adds up.

We already, as a human species, are well past "reasonable" when it comes to waste and pollution. And there are not even good reasons to make this disposable. 🫤

Eric is right about the device's merit, but (imo) not in the way it was designed.

It's efficient, but has to be with a single-use battery. The equation woulf be different when a smaller lithium cell could last for 6 months to 1 year and charge via Qi2 (place it on your phone to charge).

Make it charge wirelessly (Qi2). No charge adapter needed.

And also, why just assume people will lose the adapter? Besides, manufacturing an entirely new ring is FAR WORSE than just producing a new adapter (IF someone lose it and IF it has no Qi2 charging).

Put LFP in it, make it charge via Qi2. 🤷‍♂️

He was commenting in regards to the new ring (Index 01). Is the ring repairable? Can we replace the cell?

You will have many opportunities to expand on this idea and make an Index 02 with more functionality, so I don't assume you do this to make more money. But still the wrong design choice, imo.

Please look into what people are saying. 🫤

The facts are:
- You could make it safer with LFP (a lithium chemistry safer than silver-oxide)
- More compact (1 year rechargeable battery life)
- Lighter (Wh/g is low on silver-oxide)
- Wireless charging (no adapter to lose)
- No need for disposable tech

Same size lithium cell would last 1 year (if the silver-oxide lasts for 2 years). I might even be understating the lithium battery life because pouch cells have potentially much better Wh/L than cylindrical cells.

It could be thinner and lighter (incl. charge circuit etc.) and >6 month battery.

Easily solved by just using an LFP (LiFePo₄) cell. They are safe. Don't generalize all lithium cells

Even if you use NMC chemistry, you can make it fail in a safe way by making the inner part of the ring in steel, and design the failure mode such that the battery would expand outwards, not inwards.

It's about both!

Potentially replacing a tiny rcharging adapter (that is IF you lose it), is better than havikg to buy an entirely new manufactured ring with steel, PCB, electronics, battery, silicone etc.

Many people won't lose it. AND you can make it charge wirelessly! No dongle needed!

No, not exactly. 🫤 It was including the weight of charging ICs and pins/coils.

Lithium cells have double the Wh/gram. And you can even halve the capacity (making it 1/4th the silver-oxide capacity) and have 6 months battery use and charging.

Easily making it thinner AND lighter AND rechargeable.

No but it will die on you after the battery is depleated and you hve to constanrlt rebuy it. 🫤

As for the "no subscription", that's unecessary and a given in my opinion.

But the fact that you need to constantly rebuy it makes it a de facto "subscription". A consumable.

But it's easily avoidable by foing with a lithium chemistry that is SAFER than silver-oxide!

Lithium Ion isn't the chemistey, it's a huge umbrella of a diverse range of chemistries.

LFP (LiFePo₄) is safe a considerably safer than silver-oxide. If you want safety, that's what you want.

Calling critique for negativity doesn't mean it has no merit. 😉 You even say you "take no notice" and "ordered on the spot".

What you're essentially saying here is that you block your ears and don't listen because you already decided what your view is gonna be. 🤷‍♂️

But is it worth $75 plus shipping and import VAT (>100) and then $99 plus shipping and import VAT (>125) every couple years or even every year?

When it could've just been thinner and lighter AND rechargeable and last 6 months or a year instead (and then you just charge it)?

The problem with that statement is that it csn be thinner and lighter with a rechargeable battery. 🫤 So it's not really a trade-off, it's just making the profuct worse and less sustainable without good reason.

Besides, this is a low amount of energy we're talking. So even if it's not LFP, I wouldn't be worried. If they source quality cells and don't over-charge them, it's unlikely to have any safety implications. If the ring is designed right, I don't see how it could swell such that you cannot remove it.

Lithium cell safety is tied to stuff like top-off voltage, e.g. NMC. LFP is so safe you can even physically attack the bare cell without it catching fire or exploding.

LFP/LiFePo₄ is a chemistry. It is both mature and super safe. Nominal voltage of 3.2 V, very flat discharge curve, high efficiency.

Char lim on Bsky. 🫤

No, lithium is double the Wh per gram. So incl. charge

Lithium is safer than silver-oxide if LFP (LifePo₄). LFP has some lowered stats, but still quite good.

Actually, with pouch (not cylindrical), li-ion have better metrics. So maybe I even grossly understated li-ion metrics.

🫤 It has a non-regargeable 1.6 V silver-oxide battery cell. Once depleted, it dies.

Silver-oxide cells seem to have double the Wh/L and only half the Wh/g. So same volumetric size lithium cell would last 1 year, but be rechargeable.

Smaller lithium cell would last 6 months. Smaller + lighter ring.

I think they could fit a battery in the ring "rim" and still have it last 6 months.

I suspect the cell is fitted at the top (under the clicky button & PCB) of the ring, as the dimensions of it aligns with available silver-oxide cell dimensions. Too large in the ring, perfect fit in the click box.

Meaning, it could be the same size and same weight with 1 year usage. For 6 months usage, it could be smaller and lighter.

Lithium: (more than) double the voltage, half the current, 1/4th the voltage drop (= efficiency gains).

So, smaller, lighter, sustainable. Extra components are dirt cheap.

🙂 If this one lasts 2 years, same size rechargeable cell would last 1 year. Silver-oxide cells seem to have double the Wh/L and half the Wh/g compared to li-ion.

There are smart rings lasting a week with HR sensors, step tracking etc. Some even have screens. And they cost way less ($20-$60). 🙃

I agree. Charging is trivial. It has a one-use battery, but small li-ions cost nothing. Wireless charging (Qi2) would be universal (if the diameter is large enough).

$20 smart rings have rechargeable battery and health sensors. This is way simpler than that and have an MSRP of $99. Disposable tech.

1. My guess is yes, but if the silicone overmold seal fails, then you might get water intrusion. It might be further sealed inside, though. Erics seems to wear it all the time and want it to woek in the shower. But with 30 day warranty you have no guarantee.
2. Info page says "up to 5 min" storage.

It will die once depleted. It has a is a non-rechargeable 1.6 V silver-oxide battery cell.

Once that energy runs out, it's a paper weight or finger ornament. 🫤 Not sustainable at all.

I really hope they redesign this one. Small rechargeable li-ion cells + charging ICs cost almost nothing.

Actually, a lot is actually sold or given away. Or disposed of at local recycling stations for free. At least that's extremely common in Norway.

Most grocery stores have a recycling station for battery cells, light bulbs, electronics and drink cans/bottles.

And required for electronics stores.

Much better to dispose of at your local recycling station. It's steel, PCB + parts, silver-oxide cell and resin/plastic/silicone/TPU.

Sending it a long distance for recycling is unecessary packaging + pollution + logistics.

We even have recycling stations in most stores here.

Best: rechar. li-ion

I like the idea, but a non-rechargeable battery is a deal-breaker for me. It's not that it never needs charging, it'll just die. 🫤

And if you open it up to replace it, you need to yet again use a 1.6 V non-rechargeable cell.

I'd rather have a more complete product with charging and haptics. 🫣

I arrived at a different perspective after reading both sides' blogs among other things.

Objectively speaking, Eric's suggestions were better for the community. Maybe not for Rebble, but for the community (including the Rebble community, which I'm part of).

Opening up and decentralizing is better.