Solar-powered headphones | Hacker News Reader

Solar-powered headphones

bbc.com

51 pointsadrian_mrd102 comments

In the UK, where the BBC is hosted, solar-powered headphones are mostly a waste of time. It rains a lot and you spend a lot of time avoiding being outside. Most people are at work when the sun is highest in the sky. As others point out, most people can get through the whole day on one charge.

It would be much more efficient to put solar-panels where they can maximize their potential energy output and instead just charge normal headphones from renewable sources. Bare in mind that the creation of the solar panels themselves has a carbon offset that the application of headphones is unlikely to recoup.

I think I've only seen two kinds of devices where an integrated solar panel actually made sense: calculators as their power draw is so low the one I bought almost 20 years ago for school still works with the original (non-rechargeable) battery. And more recently a GPS sports watch which can extend the battery life with solar for hours, or days when GPS isn't used.

Other than that I agree, if you compare the power output to roof-mounted ones it seems quite pointless. Even relatively large, unwieldy USB charging panels you need to unfold can't hold up considering their area.

Looks quite handy on a USB power bank:

https://www.revk.uk/2022/09/battery-pack.html?m=1

"Obviously these various battery packs were now all flat. One of the reasons for a battery back is for when you suddenly find you need portable power for something like this.

All flat, except one!

I can only assume it was getting enough light from my office lights, even in a clear plastic box, to actually stay charged."

That is, not to charge the power bank (which would take ages) but to keep it charged during storage.

I have one of these. It looks nearly identical but mine is green.

I went motocamping for 3 weeks with somewhat limited access to electricity at times. I think my longest stretch was 3 days of camping with no access to plug in and recharge the pack. I was charging my iPhone 11, AirPods, and an Apple Watch. My phone was plugged into my motorcycle to charge/maintain while riding. The battery was positioned in a tank bag exposed to the sun for 8+ hours of riding per day.

When I eventually used the battery's full capacity, any charge from the sun was basically useless until I was able to plug into line power again. I think after nearly a full day of riding after waking up to an empty battery, I might have gotten 3% on my phone when I stopped for the evening.

When I returned home from the trip, I experimented with recharging the battery out on my apartment's veranda on the top floor with lots of sunlight all day. It took 3 or 4 days for the battery indicator light to move up 1 segment. Too long to be useful in any meaningful way.

My point in all of this, is that these cheap "solar charging" battery banks are worthless unless you can live with waiting 2+ weeks to maybe charge your device. The panels are likely larger versions of the stuff used on calculators and should not be relied on. It's a marketing gimmick.

You reminded me of something I was considering years ago: screens have incredible resolution (DPI) now, and still growing. Some technologies are based on a backlight and a mask which blocks it in the right spots to form the picture (LCD, LED Backlight) while others actively emit the right colors at every location (OLED, MicroLED).

At some point it would be pointless to keep increasing DPI due to being higher than any healthy person can resolve at a typical distance - but what if we do keep shrinking the emitting elements but arrange them more sparsely (same amount of pixels, but each one is super tiny) - and use the rest of the space for what is effectively a solar panel?

Completely stupid, or did I think of something reasonable? I could see this as a benefit especially on phones, tablets and watches (maybe glasses, absorbing invisible frequencies).

My usual beer clause applies: If anyone builds it successfully and makes millions with it, and this post ends up the earliest mention of the idea, you owe me a beer.

Or maybe someone could invent headphones that are powered by the sound-outputting device and don't have any battery at all. The signal could be transferred by a wire, for example.

I'm sure there are plenty of wired options for those who want them, but for me, at least, the experience of good wireless headphones is so much better than I'll never go back.

I used AirPods and loved them, but have gone back to wired EarPods plus Shure IEMs. I’m happy with this combo, perhaps because I don’t use earbuds very much. Plus, the EarPods’s mike is much better than wireless earbuds for calls.

I like this idea. To take it even further, I propose this wire terminate to a sturdy cylindrical plug which can rotate 360 degrees. Furthermore, if the signal were to be analog, it would allow universal compatibility with all other analog sound devices. I think this could be revolutionary.

That wouldn't let us also pass the microphone sound over that plug. I'm in doubt if this could ever be solved ... or could it?

Dang, I know you're reading this, can we get a subpage for humour?

HN has from time to time extremely good jokes!

This sequence of comments is literally a joke template. Completely unoriginal and predictable. You can get plenty of that on Reddit.

It's still funny and most things in life follow a template or a pattern, that doesn't degrade them.

I don't use Reddit.

You do you, but calling them "extremely good jokes" suggests to me you're just not familiar with this particular pattern (which if you used Reddit, trust me, you would be).

I did state in the comment to which you're responding that I don't use Reddit. So yeah, I don't see many such jokes. ^^

But how would you connect such a device to your iphone?

Cylindrical plugs are the best plugs. You never need to check the orientation.

Given how much money we spend on frivolous tech (and other) products… we should be by now producing 300% of our power via solar.

The UK isn't very rainy, it's only the 74th rainiest country. The issue is how many days are overcast

I have no idea how much headphones normally draw, so I googled and the first replacement battery I found was for the Bose QuietComfort 20, and the product listing for the battery said 240mAh/3.7V (which is 0.888 Wh) while the product listing for the headphones said "lasts 16 hours", implying 55.5 mW.

At 10% efficiency, a 3cm by 10cm PV in direct sunlight will produce 0.3 W, enough to fully charge that in about 3 hours, and the potential for charging faster than it drains whenever ambient light is at least 18.5% of direct sunlight.

Indirect sunlight on a clear day is about that at best; Overcast days are about 1% of direct sunlight; Normal office lighting is about 0.3-0.5% of direct sunlight.

So, a 1 hour lunchtime walk on a sunny day while using them, would likely be somewhere between neutral and recharging by 4 hours 20 minutes.

That said, I have no reason to expect Bose (first random search result) to optimise for minimal power draw, given how small and light the battery is and still gets 16 hours, and I don't know if there's room for improvement with these in that regard.

Ok, but let's not fool ourselves that this is to save the mains electric grid from the power used to charge these things. This is for convenience, not environmentalism.

The amount of power used by headphones is tiny. Which is lucky, because the amount of power that a small inefficient solar cell like that can collect in artificial lighting is tiny as well. For reference, my Bose noise-cancelling headphones use something on the order of a tenth of a Watt. My microwave oven uses 5W just to keep the clock flashing "--:--".

I have a 14-year old wristwatch, which is solar powered. I haven't had to change a battery in it ever. It's convenience, and it's neat, but that's it.

This isn’t necessarily the full picture.

Whenever I see efficiency gains, I tend to look for reductions in materials utilizations, and sometimes I might find a case for environmentalism (on some axis).

I work in the technical area that enables flexible solar panels to exist at large volume (replacing energy intensive rigid glass with flexible barrier films). The manufactures of these headsets note that it allows for a larger volume reduction in batteries when integrated across 100,000s units compared to the addition of the panel itself.

Also, the technology supports the global supply chain to continue to lower the cost of PV which is good for the environment.

An eventual goal is the ability to quickly unroll massive installations of PV on rooftops that are as durable as the roof itself.

I bought the Urbanista headphones mentioned in the article. That was 6 months ago, I've used them daily indoors for meetings and listening to music, and I had to charge them with a cable only once in those six months. My desk is by a window and I live in Barcelona, so the headphones get quite a lot of indirect sunlight. Still, they feel like magic to me.

How powerful of a computing device could be powered by a small solar panel these days?

We had solar powered calculators in the 1980s, but with chips being so much more energy efficient now, I imagine we could build a much more impressive device with no battery.

Not really. To power an Arduino you need a much bigger solar panel than a calculator. Those calculators aren't necessarily inefficient, they just hardly do anything at all. You really can't do much more with a solar panel that size, it hardly captures any energy.

Arduino’s are very power hungry compared to low power electronics. RFID tags for example are extremely low power.

That said, there are solar powered scientific calculators which have dramatically more computing power and much larger displays than what people think of a solar calculators and still operate indoors at low light levels. Ex: TI-36X Pro

A modern redesign could probably probably get ~1 GFLOPs, but those things are more designed for standardized tests than to be a useful tool.

Thanks, this is a great data point. TI has some higher end calculators which are not solar powered, so that gives a good estimate of what was possible (at least when they last redesigned them).

logitech used to get away with solar cells on the K750. It did sometimes die if left without much light but I was impressed it could operate as well as it did without direct sunlight.

Thanks, this is a great example of what’s possible now, since it has wireless capabilities.

We have them in all of our meeting rooms in our office, and they must charge enough just from the indoor lighting because they have been working for years without any battery changes(I don't think you even can change the battery in fact).

The Microchip brand micro in the arduino wouldn't be the right choice here. Something like the TI MSP430 would, it runs on very very low power requirements and has sleep functions that have insanely low power draw.

This is exactly the answer I was looking for, thank you. This TI chip draws a little more power during computing than a calculator solar panel would provide, but it could easily work if it stayed in sleep mode part of the time.

You could probably get 2W from a wide over-ear band in direct sunlight. Maybe that's 2-4 hours per day, with indirect light scattered around the day.

If you get say, 2W*6h=12Wh/day, you could afford about 15mA/hr @3.3V. That might be able to power a set of wireless headphones with a reasonably-sized battery, if you left them on a windowsill in direct sunlight when you weren't using them.

Modern designs will probably use monocrystalline cells, but old solar-powered calculators used amorphous cells. Those are less efficient, but they can recover a trickle of energy from weaker light sources such as indoors or cloudy days.

I also wonder what sort of materials they'll use. Plastics don't usually handle excessive UV exposure well.

Calculators are kind of a special case. When you are not pressing a button they are doing literally nothing, and maintaining the state of the LCD takes only microwatts.

They use so little power that many "solar" calculators are fake, the "solar panel" is decorative only and a hidden button cell battery provides a decade of battery life: https://youtu.be/uLTDuGhqE2w

My childhood would have been so much more boring if I couldn't starve my calculator of light and watch the screen get dim

Is fake solar powered calculators a new thing or am I misremembering my childhood? I remember entertaining myself[1] by covering the solar cell and watching the screen go blank.

Edit: nvm, YouTube comments and even a sibling comment to this mentioned the same thing, my childhood memories are real. After watching the YouTube video the guy took apart five calculators and only 2 had fake solar cells, so not what I expected.

[1] yeah, pre Internet entertainment was boring in comparison.

The quicklook of these on LTT was pretty favorable. They actually seem pretty neat. I prefer earbuds for running though so not for me. Like the idea though

How often do people use their headphones outdoors? I would be very surprised if the average time outdoor over the lifetime of a headphone to be over 5%.

The article states that the kind of PV charger they're using works under any light source, including artificial lighting.

It's about half as efficient at converting light into electricity as current best rooftop panels, and these ones are way thinner.

OK, but efficiency at converting light into electricity doesn't mean much if the total amount of light available for conversion is very low -- which it is in almost all indoor situations.

The illumination level in a brightly-lit office is typically on the order of 300 lux, compared to 100,000 lux for direct sunlight. (Residential spaces are often even dimmer.) So if, as they claim, this device can gain 1 hour of charge in 20 minutes in direct sunlight, it would take on the order of 100 hours to collect the same amount of energy indoors.

The statement that "the panels can also create some power from artificial light" is technically true, but "some" is doing a lot of heavy lifting in that sentence.

> this device can gain 1 hour of charge in 20 minutes in direct sunlight, it would take on the order of 100 hours to collect the same amount of energy indoors

Depending how frequent and heavy of a user you are, the economics may work out such that they'll be passively charged enough and never require active charging.

Related idea: It'd be cool if cellphones could charge in light whilst powered off. Then when they get old, they'll sit around and always be topped up and ready to go.

The physics just doesn’t work that way. Our sun produces about 11MW/m^2 (changes significantly due to atmospheric conditions) but there is no artificial lighting that will even be 0.0001% of those number.

My whole room is lighted by maybe 20W of LEDs, so it gets what, 5W of light? Very few of those Watts hit the solar panel.

Depends on the person I guess? Or maybe how much time they spend walking. I used to use headphones almost exclusively while walking, and generally only used stereo speakers at home. I don’t listen to anything while walking these days because I’m generally paying full attention to my pup, music would be an unwanted distraction. But I do see lots of other people wearing headphones while we’re out walking. And I don’t have that stereo anymore, I generally only use my MBP’s built in speakers at home now. I really don’t like wearing headphones at all though.

Indoor solar powered devices have existed for decades (like calculators). The article even explicitly states that these can be charged from indoor light.

Sure, there are pocket calculators that can run off of ambient indoor lighting, but they have to be designed to run on a truly miniscule energy budget -- on the order of a fraction of a milliwatt.

You seem to have missed the second sentence in what you replied to (and the relevant bit if TFA):

> The article even explicitly states that these can be charged from indoor light.

These apparently can also gain useful charge from much smaller energy sources than direct sunlight, including typical indoor light levels. Even if it isn't enough to run them indefinitely, it could extend their run-time between plugged-in charges.

No, I didn't miss it.

You'll note, if you read carefully, that the article only says they can be charged from indoor light, which I don't doubt is true. It doesn't say they can get a useful amount of energy indoors. The only concrete numbers quoted are for direct sunlight, which is several orders of magnitude more intense than ambient indoor lighting.

> No, I didn't miss it.

It seemed so, or that you were ignoring it, from what you write. Perhaps offer more clarity in future to avoid such confusion.

> the article only says they can be charged from indoor light

The article says they can be charged from indoor light. Adding “only” there I think is needlessly negative. The article goes on to describe how this is expected/hoped to be useful, charging between uses even if (unlike direct sunlight) it is not enough to maintain power during prolonged use, which strongly implies a useful amount of energy if thought to be harvestable in typical indoor conditions.

> Perhaps offer more clarity in future to avoid such confusion.

Sorry, I'll be more explicit: I give absolutely no credence to what a manufacturer "expects" or "hopes" or "strongly implies" their product to be able to do in a thinly-veiled press release, especially when they're unwilling to give any concrete facts to back those hopes up.

I likewise, given how often people don't read things before responding to or about them, don't give the benefit of the doubt when someone's response looks like they may not have considered details that are openly presented.

Feel free to be a cynic, it is often a healthy position IMO, but you'll be less stressed if you try not to let yourself get offended (or just surprised) when others are too, or consider how others might read you incorrectly which can be corrected with a little detail of your PoV (other than it is contrary to another one) up front.

A "100 Watt equivalent" LED bulb uses 13 actual Watts. Let's be generous, and say it's 10W of light, 3W heat.

Let's be generous again, and completely wrap the bulb in 50% efficient photovoltaic, feed that into a 50% efficient battery charger.

You now have 2.5 Watts.

It just doesn't add up.

Minuscule by 80s standards. But also using smaller solar panels, less efficient solar panels, less efficient chipsets, and a display too.

Technology has moved on considerably since solar powered calculations were a thing. So I don’t doubt these headphones are possible.

To be honest, I’m really surprised at all the armchair physicists here posting snarky comments. Maybe if Apple had released it people would be more complimentary…?

Apple headphones have full-on computers inside them. No way with a B able to operate with power from solar cells

Sorry, that Apple comment was intended to be taken sarcastically rather than literally -- I really should have made that clear in the comment itself.

The point being: it's disappointing just how skeptical everyone is being. I'm not suggesting that the PR hasn't given favorable figures but there might still be a genuinely great product here.

Awkward for me because I am usually in your position. I do like where your heart is. But the physics just won’t work out. You cannot power modern noise suppression, speaker drivers, amp, and Bluetooth with solar, using today’s tech, period.

You can run headphones without any battery what-so-ever when wired to an external amp via an audio jack, and the amount of power sent over that is small. Also it's deceptive to include the amp and speaker drivers as separate items in your list because it is the amp that powers the speakers. Maybe you mean DAC? But DACs are really cheap to power these days so I'm really not concerned about their power draw.

There's no mention in the article of automatic noise cancelling. "noise suppression" is an acoustic design rather than electronic one. Eg the way the hardware cups your ears to dampen external sounds. So noise suppression costs nothing in terms of power draw. Whereas "noise cancelling" is what requires a mic and some onboard computation to inverse the sound wave, which will obviously have a power draw. But noise cancelling isn't an "always on" piece of technology, it's something the wearer can enable or disable. So it might be that when running low battery power and thus more dependent on solar, noise cancelling needs to be disabled (assuming this device even ships with it, not all headphones do) and as a wearer you're more dependent on the acoustic properties of the headphones to reduce external noises.

So we just have bluetooth and an amp left to power. It may well be that to run the device "fully solar" (ie with zero reserve in the battery) the device has to be wired to the music player via a traditional TRS audio jack. This is already a pretty common thing for bluetooth headphones to support when low on power. Thus the solar cells would be designed to charge the battery when the headphones are off and supplement the battery while in heavy usage.

That still seems like a massive win to me because if you use your headphones sporadically or even just have a few hours in the day when you're not using them, you still end up not having to think about recharging your headphones every time you want to use it. And that's exactly how this device is reported by the BBC: not as something that never needs to be charged or is "fully solar" but instead as something that uses solar energy to reduce the need to charge.

(I've built speakers and other audio hardware. So while I'm far from an electrical engineer, I'm also not a total noob in this field)

I wear headphones constantly outdoors (walking/running) but can’t recall the last time I had them on indoors. If I’m indoors I’m using good speakers.

I use headphones exclusively outside on our farm. All of the equipment makes a lot of noise and decent headphones help with the noise. And because my wife gets the 'new tractor' with a cab, radio, and AC, I get the 'old tractor' and get to sit out in the sun from sun up to sun down during hay cutting 3 or 4 times a year. I've yet to have a pair of headphone last a full day. This could be cool and keep me from having to keep 3 pairs on hand.

I freely admit that I am an outlier, but I'm used to people not understanding that a large segment of the popular leads totally different lives with totally different needs than most people.

You'd think someone would have come up with some form of auxiliary power pack for headphones, maybe one of those dual-battery solutions where you have a small cell on either side and can replace them in turns to keep it nice and balanced while still being able to keep using it all day long. Maybe the market is too small, or it already exists and we don't know about it yet.

Sounds like you just want the ability to swap in a charged battery with minimal downtime?

Pretty sure those exist already, I know Steelseries produce some headphones with that feature.

That's pretty neat, they even look like BL-5C batteries (if you squint..) https://steelseries.com/gaming-accessories/battery-pack

Didn't know they actually went through with that. I was thinking along the lines of those very old laptops that had dual NiCd banks so you could swap them without shutting down.

Bose QC were powered by removable battery until the QC 35. I'm sure you can still get a QC 25 online somewhere.

I took apart an old bluetooth speaker set, took the gumstick receiver/amplifier/battery charger combo, and slapped that into a set of headphones with an 18650 cell on each side. Lasted days straight. That was a decade ago. I'm surprised nobody's bothered to make large cans with large battery capacity.

I think the last part is important though “large segment of the popular leads totally different lives”. That’s mainly why I said average, I’m more than happy to be proven wrong but if your statement is true, the statistics will show it. Like if the average is 5% outdoor +/- 2%, then it’s obvious that a large segments doesn’t necessarily have a different need.

But this is why small companies are so important. A small company that knows it's client base well, even if it's husband and wife farmers that have a product need, that can still be hundreds of thousands of people and make it not only a successful company, but one that serves these small "outliers".

Long tail yadda yadda.

There are lots of (expensive) headphones that will last 30 hours or more of playback, including the excellent Sony mx 1000 line. They have great noise cancellation, and older versions are often on sale for a significant discount.

I only use earphones, just because I find it more comfortable, but almost exclusively. I have no (extremely little) need for them indoors, I (almost always) prefer speakers there.

I guess I'd say that's a reasonable estimate for time spent outside as a percentage of total time, but of time in use, I'd imagine that could be off by an order of magnitude. Probably depends where you live and the weather outside.

I don't mean to be blunt, but am I right in saying that you are from the US?

I ONLY wear my headphones outside. I bought them especially for commuting to work on public transport and walking to the shops. That doesn't seem unusual where I'm from. A lot of people wear their headphones outside.

I mean, I also have a headset at my desk for calls, but that's not what these are for.

Eh? Most people use speakers at home instead of headphones and most indoor time is spent at home. So I'd imagine plenty of people use speakers outdoors.

I, personally, exclusively use headphones and I still use my headphones outside all the time - while walking, working outside, gardening, snow shoveling, etc. Even just relaxing.

Dont (non active noise cancelling) headphones already not use any power?

Wired headphones get power from whatever they are plugged into.

Once you decide you don’t want to physically connected to the grid while wearing the headphones, you’re going to carry a battery around (or generate power with solar or something). If you’re also carrying some additional device (eg. a phone or mp3 player) along with the headphones and you’re wired into that device, you could have that device handle the power.

Nowadays I’m frequently switching my listening and speaking between different devices, some of which are on my person and some aren’t. So plugging the headphones whatever I’m currently using would be inconvenient and restrict my freedom of movement. Therefore it’s nice to have for the headphones to contain their own battery and do automatic switching between different input devices.

Solar sounds like a gimmick to me, the battery life of the headphones is not any issue anymore.

Only if they are wired. The article is about wireless headphones and people forgetting to charge them. It's a bit advertorial-ish because this is exactly the product that a brand has launched just now.

Technically it could help but just like solar-powered garden lights, it's a race you can't win with ambient light.

If someone were to find an amazing headmounted-solar-power-source, it would have to be so good you'd be able to charge your mobile devices with it (or you'd have to walk in the sun all day long to keep it going and have enough of a charge for the night).

Yeah, since you're already listening to something using a powered device it'd certainly be far better for the environment to not add another toxic battery in your headphones and just plug them into whatever your listening to.

Remember when headphones were wired and didn't need power?

I do. But the biggest e-waste manufacturers in the world (Apple, Samsung, etc.) decided they can now sell you Bluetooth earbuds too, so removing the jack was a nice nudge to force you to buy more of their e-waste.

I'm not against Bluetooth earbuds but I'm against removing the jack.

https://miscircuitos.com/lab-characterization-of-the-solar-c...

No. The available surface area is too low.

We’re not talking about powering a car here. Most headphones have a tiny tiny energy draw to maximise the energy of their tiny lightweight battery.

'Currently the tech can create one hour's worth of power "from just 20 minutes of English or Swedish summer sunshine".'

So ... 20 minutes use per year.

Nice.

Presumably, it is referring to strength of sunlight at that latitude. 3:1 runtime to charge time for strong solar lighting really isn't bad at all if the cells are durable enough for a wearable item and the speakers don't suck.

I think GP is joking about getting just 6m40s of sunshine per year in England/Sweden.

From the article:

"The solar-powered headphones still have a built-in battery that can power up to 80 hours of playback time. It is this that the Powerfoyle strip charges. Mr Fili says that currently the tech can create one hour's worth of power "from just 20 minutes of English or Swedish summer sunshine"."

A very bold claim, I do wonder if that's with the strip placed optimally facing the sun, and not integrated into a headset.

The idea of a solar jacket to keep a hikers satellite phone topped off sounds more attractive though.

Back of the envelope calculations.

Assume:

* solar panel is about 1.5cm x 20cm = 0.003m^2

* Efficiency = 10%

* solar insulation is 1000W/m^2

Power = 0.3W

In 20 min you gain, 0.3x1/3=0.1Wh of energy.

Now, these random Sony headphones [1] have 30h life with a battery of 3.7V, 1200mAh [2]. This means they consume 3.7*1200m/30 = 0.148Wh per hour.

Seems like claim is roughly in the ballpark.

[1] https://www.amazon.ca/dp/B0863TXGM3 [2] https://www.amazon.ca/dp/B08YQX76B1

To add to this, each apple airpod earbud has a 93mWh (0.093Wh) battery and can in theory last about 6 hours. So, a headband that can capture 0.1Wh of energy in 20 min would recharge about 3 hours worth of airpod listening time.

It's definitely in the right order of magnitude, this could definitely be doable.

This could make a lot of sense for the student market, where you listen to music/podcasts/whatever between classes and then the headphones get a decent charge when you walk between buildings, walk home, etc.

Summer sunshine is also like an order of magnitude more W/m^2 than overcast winter day, at least up north.

depends on what kind, you could have head-band style with thin film over the surfaces and low power in ear transducers, i'd probably buy none (granted the pv film doesn't degrade in a year)

which reminds me that I regularly find old PV pocket calc, with I forgot what kind of oxide they used, still working fine..

Solar hats. The next must-have.

Around 10 years ago Logitech sold solar-powered wireless keyboards (maybe they still do). They were pretty nice, and not having to deal with wires or batteries ever is something I miss now that I've switched over to mechanical keyboards.

Hopefully the "make everything solar powered" idea catches on at some point. I feel like solar-powered phones and tablets with e-ink displays should exist by now.

I have the first version of those Adidas headphones, that do not come with the solar panels but are otherwise the same.

I wear them 8 hours per day at the office, at the gym, while jogging etc. Light and stay on your head well. Highly recommended.

The new version looks to be twice the cost so I don't think I'll upgrade anytime soon but I'd probably get them if these fail out of warranty.

The density of e-waste goes up.

Coming up next, headphones that are powered by the bobbing of your head.

Not a completely unfeasible idea. Kinetically wound/charged watches have been a thing for decades

I didn’t know BBC were running adverts these days…

That was my first thought as well. It will be interesting to see future applications of this technology. If they can get the costs down and the charging is actually efficient enough, it'll be worth it.

Never heard of Top Gear?

https://www.bbc.com/editorialguidelines/commercial-services#...

Why does no one create solar powered Smartphones though?

The amount of power required by a smart phone massively exceeds the amount of power that can be supplied by the area available

And as always... https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...

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