New battery has life so long you may never have to recharge | Hacker News Reader

New battery has life so long you may never have to recharge

neowin.net

55 pointsBluestein58 comments

Not comparable to a real battery any time soon based on the paper https://pubs.rsc.org/en/content/articlelanding/2025/cc/d4cc0...

> The perovskite betavoltaic cell achieved impressive parameters, including a short-circuit current density of 15.01 nA cm−2, an open-circuit voltage of 2.75 mV, and an energy conversion efficiency of 1.83%, all of which represent significant improvements over previous works.

Will it ever be comparable to a "real" battery? The energy output has a clear upper limit. Are there materials that produce only beta particles at a high enough rate per gram that could power a cell phone with a half life of more than a few days?

Assuming you could get these to 10% efficiency (which is theoretically possible) and a phone needs 0.2W of energy to function then you would need a source capable of supplying 2W of energy (of which 1.8W would be dissipated as heat). The phone would be fairly hot all the time but 2W could be dissipated without it overheating in most environments. Strontium 90 generates 0.95 W/g so in theory a few grams of strontium 90 would be enough to power your phone for many decades (the half life is 28 years). But if someone were to accidentally put such a phone into an insulating material it might overheat and become a dangerous radioactive mess!

> and a phone needs 0.2W of energy to function

For an arbitrary definition of "function". I don't think a modern phone would achieve a meaningful function at that level. The cellular modem alone blows past that budget many times over. Even an old rotary phone went over 1W.

Apple's efficient 5G "C1" modem used in the iPhone 16e is still at ~0.7W. The Qualcomm models used in the iPhone 16 are 0.8-0.9W.

It might charge a capacitor/"real battery" most of the day and then be available when needed.

At the end of the day if the phone draws more power than the power source provides, you're limited to bursts of activity until the capacitor is depleted and then the phone is dead while the capacitor recharges. 0.2W is barely enough to power an idling phone, let alone charge an extra capacitor.

Today we juggle with ~15+Wh batteries (the "capacitor") and 30+W fast chargers (the "power source") and still need better.

It doesn't need to replace conventional charging. But a phone that gained charge when unused might still be useful - being able to make a call later might be better than never.

It would be great if used as an "emergency power source". I see this equivalent to the satellite SOS systems - not useful for daily use but essential in emergencies. You know you can get brief emergency function every x hours.

But for the question asked higher in the thread, it would never be comparable to a "real" battery. This would be a very special purpose battery.

If you found such a material, would you want it in your pocket? Or someone else's pocket, where it could break in an accident?

You are right. They are definitely not ordinary consumer products. However, they might be useful where recharging or exchanging a battery is impossible or associated with serious disadvantages.

For example, in the past cardiac pacemakers had been used with nuclear batteries. However, there is a risk that the pacemaker will be “forgotten” after death, and something that is actually radioactive hazardous waste will be disposed of via crematoria or cemeteries.

Another area of application for nuclear batteries is space exploration.

I think the tradition is someone else's pocket in some other country.

Dear battery technology claimant,

Thank you for your submission of proposed new revolutionary battery technology. Your new technology claims to be superior to existing lithium-ion technology and is just around the corner from taking over the world. Unfortunately your technology will likely fail, because:

[ ] it is impractical to manufacture at scale.

[ ] it will be too expensive for users.

[ ] it suffers from too few recharge cycles.

[ ] it is incapable of delivering current at sufficient levels.

[ ] it lacks thermal stability at low or high temperatures.

[ ] it lacks the energy density to make it sufficiently portable.

[ ] it has too short of a lifetime.

[ ] its charge rate is too slow.

[ ] its materials are too toxic.

[ ] it is too likely to catch fire or explode.

[ ] it is too minimal of a step forward for anybody to care.

[ ] this was already done 20 years ago and didn't work then.

[ ] by this time it ships li-ion advances will match it.

[ ] your claims are lies

Cute, but you're supposed to actually mark the applicable ones.

More importantly, there is no claim that it is better than li-ion. They're targeting low power devices used for very long times where replacement is impossible or undesirable.

I think the idea is that the person making the claim is supposed to dutifully fill out the form

Your comment applies to most of these articles. However, this one is a bit different. It is actually a niche product for specific devices, especially those that require decades of operation without recharging.

Great, we can use them to store all that energy we'll get from our fusion reactors!

Actually, it can use some waste from our nuclear reactors.

These batteries provide milliwatt level power. Enough to power, maybe a clock circuit without display.

My water company installed a smart meter. Inside is a 30 year battery. When the battery is depleted it should be time to replace the whole meter.

Probably good for the dark, remote, lots of space applications. E.g. a radio beacon near the poles.

RTGs (radioisotope thermoelectric generator) are already in use for both deeps space and remote applications. Not sure how this differ. Maybe better efficiency? Still, why is it called a battery instead of a generator?

Oh, maybe size as RTGs are bulky.

edit: there have been very small RTGs for use in pacemakers. The difference is really that these are not thermal but use the beta flux directly.

The Soviet Union also had mass-produced RTGs for powering equipment in remote locations on earth, like light houses

https://en.m.wikipedia.org/wiki/Beta-M

Oh, RTG pacemakers were already betavoltaic [1]. So this is really an incremental improvement on existing tech.

[1] https://en.wikipedia.org/wiki/Betavoltaic_device.

Maximum wattage of the battery would also be maximum wattage of the radio signal.

Wouldn't it be feasible to add a tiny battery or capacitor? Assuming the radio doesn't need to transmit continuously it can be powered via those which are then powered by the "forever battery".

Yeah you'd need a lot of them. Instead if a AA battery maybe you need a truck's worth of this. But if it means you dont need to go back for a while...

It is easy to imagine a future where tiny nano-electronics are embedded into pretty much everything everywhere. The plants in the field that call for treatment at the first sign of insects or infection, for example.

This reminds me of those break-through articles about using Scotch tape as mass storage medium.

Just don't peel it, as the resulting X-rays will probably wipe it!

https://www.technologyreview.com/2008/10/23/217918/x-rays-ma...

Directions unclear: made graphene instead - https://youtu.be/LwmxSjyd

Does this involve a sharpie

Excellent for all those applications where you need... Almost no power at all.

The example given in the article was a pacemaker.

I'm guessing there _are_ applications where you don't need a lot of power, but you do want it over a long time and without needing to charge or replace batteries.

It's also easy to imagine places where, whilst power is available, there are manufacturing advantages in not needing to. For example it might make economic sense to have self-powered wirelessly-connected sensors on car bumpers just to avoid the manufacturing cost of wiring them all up?

Pacemakers need a hell of a lot of power for a short amount of time occasionally. To do that you need to store it in something which can be discharged quickly and is low impedance. Which is a capacitor.

This thing generates so little power you couldn’t charge a capacitor up quickly enough or keep one charged with the leakage.

You're nothing thinking this through. It could trickle charge a capacitor or supercapacitor that has a very low self-discharge rate. There's a circuit called a Joule Thief that can extract usable power from very low voltage sources. There are other tricks to do voltage multiplication like using diodes and capacitors, but there are also micropower switching boost converters too.

Yes I know this. I’m a qualified EE. Go do the numbers on a supercap with quoted leakage and a decent error margin.

You’re talking about an implantable defibrilator, not a pacemaker?

No. The heart is relatively high impedance. You need a low impedance source to drive it even on a trivial basis.

Wireless sensors? I'm sure the engineers will see the ether works fine in a lab but as soon as you try it in the real world it vanishes.

We already have wireless sensors in cars - tyre pressure monitors.

A lot of pacemakers on the market today are remote access. They can be dialled into by your doctor and adjusted, in concert with live alerts and logs. Thats not infintisimal power requirements. (Cellular is cheap, but not nothing.)

Whilst we do have long lasting applications in places, a pacemaker was a poor choice of the article.

I shudder at the hackability potential of these things ...

I get your point, but there's a surprising number of those.

Unless you want to power a device with Microsoft Teams running on it

How does a cell like this work? Is it directly turning the flux of electrons from beta decay into usable current?

This one is beta, so yes direct conversion to current. ITs not a matter of alligator clips on left and right sides; and your internal wires need survive radiation and usually high heat.

My guess is these could have biomedical applications. Other than that, I doubt they would become widespread. The radioactive nature makes it unlikely to be used on the consumer market outside of maybe a few niches due to disposal concerns and the low power output limits it's possible applications.

So what's the maximum voltage and current that you can pull from one?

"an open-circuit voltage of 2.75 mV"

This looks like a big improvement over the current state-of-the-art.

https://en.wikipedia.org/wiki/Betavoltaic_device

The Thing that the heading missed,

"which could power small devices for decades"

This nuclear battery tech is wild. Tiny devices that could run for decades without a recharge changes the game for things like sensors, medical implants or space gear. Still early but if they improve the efficiency, it could seriously shift how we think about power.

Tech bros love reinventing things from the 70's

http://large.stanford.edu/courses/2015/ph241/degraw2/

i don't think you can 'recharge' a nuclear battery.

Bombard it with radiation and transmute it to a decaying element

I feel like I've been reading news like this for over years, yet these breakthroughs never make it to market.

Ctrl+F "nuclear"

Nope. I'm fine with recharging my batteries every day, thank you very much.

The least the society needs is nuclear waste thrown all over the place. People still didn't learn how to recycle regular batteries.

Except from the name ("radioactivity", "nuclear") its not the same thing that killed people in chernobyl.

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