30-Year Laptop Battery?

October 9, 2007 6:46 AM

Betavoltaic Batteries are supposed to last 30 years, run cool, and be inert and harmless when depleted. The batteries, which generate electricity from radioactive decay, have a 50-year development history, but breakthroughs at the U.S. Air Force Research Lab are said to make the batteries practical for use in consumer applications. So why doesn't the Air Force lab's website feature this discovery? Maybe because it's a hoax, or a scam.
posted by Kirth Gerson (22 comments total)

I don't doubt that it's a hoax, just like all the other super-batteries and super-engines that people have talked about for the last umpty years. But even if it is real, it'd never make it to market, since there's no profit in selling a battery that people only have to buy once every thirty years.
posted by Faint of Butt at 6:51 AM on October 9, 2007

That's why Energizer is paying off the Air Force to suppress this technology.
posted by M.C. Lo-Carb! at 6:57 AM on October 9, 2007

'Although betavoltaic batteries sound Nuclear they’re not'

Hrm. Someone there doesn't quite get the word 'nuclear'.

Anyway, I can't see it being useful. To generate enough electricity to power a laptop for any length of time you'd probably be needing worryingly radioactive material.
posted by edd at 6:58 AM on October 9, 2007

"Careful not to get these batteries too near your eyes or groin."
posted by kaseijin at 7:09 AM on October 9, 2007

These things sound like a scam. The shielding alone would make these huge even if they worked. But the underlying principle, generating electricity from radioactive decay, is sound, and has been powering the Voyager spacecraft low these 40 years.
posted by Pastabagel at 7:22 AM on October 9, 2007

Beta particle shielding doesn't have to be very thick. The main issue on that front is physically containing it to avoid leaks etc., I'd have thought (and the fact you probably don't want to be selling large quantities of radioactive material to Joe Public).
posted by edd at 7:28 AM on October 9, 2007

To the open market, I could see the government not letting these things get out. A. they are radioactive, B. where is the profitability. I can, however, see these batteries having a lot of space exploration possibilities.
posted by Mastercheddaar at 7:39 AM on October 9, 2007

Perhaps a laptop isn't the best application for a radioactive battery.
posted by Blazecock Pileon at 7:40 AM on October 9, 2007

once again, modern science tries to make me sterile.

what gives, modern science?
posted by mr_book at 7:57 AM on October 9, 2007

Perhaps a laptop isn't the best application for a radioactive battery. - Blazecock Pileon


...eponysterical?
posted by kaseijin at 8:42 AM on October 9, 2007 [1 favorite]

I've spent the past 5+ years doing primarily thermoelectrics research with a substantial chunk of solar work on the side. This is 99.9% horseshit. It is possible to get some energy out of a method like this (it's basically a very-wide-bandgap solar cell), but it's an insignificant amount.

Pastabagel mentions radioisotope thermoelectric generators (RTG), which use a thermoelectric to convert heat from decaying plutonium into electrical energy, but the power densities remain small, the device sizes are relatively small, and the prospects of this for powering a laptop using a chunk of radioactive material are slim.
posted by JMOZ at 8:48 AM on October 9, 2007

I thought there was an RTG system available for (exclusively) marine applications. But when I've tried to Google it, I've not found it.
posted by Ethereal Bligh at 9:00 AM on October 9, 2007

not sure why this is a FPP since even the poster admits that it's not that interesting. From what I gathered when I came across this the things are "real" in the sense that such a thing does exits but the problem is that

a) the power density is low

b) they generate power all the time, whether the device it's powering is "on" or not - so it'll get very hot if you stop using it. Not much use for a laptop.

c) their power output continuously degrades - basically after the half life of the material they will put out half as much power. Given that you can't regulate the power output (see (b)), then you have the problem that at the beginning of the life of the battery you're going to have to get rid of excess power (presumably as heat) and then at a certain point it will be producing less power than you require, so be useless - yet it will still be generating power and still be radioactive.

so - not much use I'm afraid. Pity.
posted by silence at 10:09 AM on October 9, 2007

Oh sure, it’s a hoax. Like the 100 mpg carborator or the water engine or the aliens at Area 102 (twice as secret as Area 51).

“Perhaps a laptop isn't the best application for a radioactive battery.”

Nah, it’s fine.
*turns on laptop*
OW! My Testicles!
*turns off*

*turns laptop on again*
Huh. Didn’t hurt that time.
posted by Smedleyman at 10:26 AM on October 9, 2007

not sure why this is a FPP since even the poster admits that it's not that interesting.

I do? Where?
posted by Kirth Gerson at 10:39 AM on October 9, 2007

edd: (and the fact you probably don't want to be selling large quantities of radioactive material to Joe Public).

I don't know, I'm sort of amused at the idea of mutually-assured-destruction being a deterrent in HOA disputes.

"Frank, we've been noticing that your grass is at least a full inch longer than our neighborhood has agreed to. You will need to cut it or we are going to cut off our diplomatic relations"

"Don't push me Steve, just remember, if you attempt any kind of preemptive strike, my defense system will launch and that will be the end of both of us."
posted by quin at 11:26 AM on October 9, 2007

“Are you mad? Really, really mad? Then get Neighborhood Nuclear Superiority!”
posted by Ethereal Bligh at 11:38 AM on October 9, 2007

I'm in awe at the sheer stupidity of this battery concept. Let's look at this brilliant new technology against a 2500 mAH Duracell AA on (1) portability (2) safety (3) cost (4) longevity.

Portability: Tritium generates 5.7 useful keV per decay - the rest is carried off in the antineutrino. For 1 watt over 10 years or 3E8 Joules total energy, that's 1.9E24 tritium decays or 10 grams of tritium. In reality, you won't get over 25% conversion efficiency, and the shielding and radiothermal generation will be a massive part of the battery. For ONE LOUSY WATT, we're up to 40 grams of tritium and maybe 1kg of associated machinery. The entire world's commercial tritium demand is 400 grams per year, by the way. The Duracell AA weighs 22 grams and does not consume 10% of the entire world's commercial tritium. Advantage: Duracell.

Safety: You're walking around with 40 freaking grams of tritium, a beta-emitter which is very toxic on inhalation and ingestion. This is like Osama bin Laden's wet dream or something. Toxnet says "the radiobiological effects of tritium beta radiation in the form of oxide is 2 to 6 times higher than for gamma radiation of cesium-137Cs". In fairness, you probably wouldn't want to eat the Duracell either, but you also can't poison a city with it. Advantage: Duracell.

Cost: "Tritium costs in the range $84000 to $130000 per gram" (fusion.ucla.edu). That's $4,000,000 for the materials costs for this battery. The Duracell costs $12.79 for 16 from Staples.

Longevity: The radioactive battery does admittedly last a lot longer than the Duracell. On the other hand, after 12.3 years, its power output is only half what it was. For most conceivable applications, this is when you'd throw it away. But wait... you've still got 20 freaking grams of tritium left in there! What are you going to do with that? On the other hand, the Duracell AA can be easily changed (since it doesn't weigh several kilograms) and disposed of in a recycling bin. If you're using the battery somewhere remote, like an orbiting satellite, tritium is still a horrible technology, compared to something like cesium or plutonium RTG's, which have a much longer half life.

Conclusion: This technology is over four million times worse than current batteries in every possible way. I can't think of any proposed invention that has ever failed harder. I expect the Pentagon will love it.
posted by Bletch at 12:45 PM on October 9, 2007 [3 favorites]

When I read something about this a few years ago, some researchers were thinking about using several of them to extend the life of the main battery in small electronic devices like cell phones by acting as rechargers. It sounded like a reasonable use to me, but then I know very, very little about battery technology.
posted by moonbiter at 1:03 PM on October 9, 2007

Why not use Strontium-90?
posted by mr_roboto at 1:04 PM on October 9, 2007

Then I read Bletch's comment ...
posted by moonbiter at 1:05 PM on October 9, 2007

Betavoltaic is a scam.

Now, if we could just hook Metafilter up to some leads, maybe we could devise a Bitchavoltaic power source. Need more juice? Just start a LOLXtians thread or something similar. Genius, I say.
posted by Benny Andajetz at 2:36 PM on October 9, 2007