Safety and legality aside, could you design a phone that never needed to be charged?

[Camacha]

This technology already exists...

https://c1.staticflickr.com/9/8151/7135713117_a1be059734_z.jpg

Satisfying clickity noises included!

[Tommygun]

I would go with this approach:

[RuBisCO]

Here are the power sources that could do that

Pu238: Gives off about .5 watts per gram with a half life of over 80 years, a thermal electric converter at 5% efficiency could generate .5 watts (enough to keep a phone charged) with 20 grams. At several thousand dollars gram this would be an expensive phone.

Bio-electric fuel cell: Yeah sure we could make it operate on sugar or ketone bodies from your blood, we would need to install a fuel cell in your body that can produce up to half a watt, operate continuously for years and be medically certified, experimental research has been undertake on animals but I think this one is still many years away.

Solar power: The back of a smart phone has about 0.01 m^2 surface area, a really efficient and expensive GaAs solar panel could do 30% efficiency, faced into the sun it could produced 3 watts, a 3000mAH 3.5V battery can hold about 10 WH and would be charged in 3-4 hours of direct sunlight, perhaps a full day in realistic weather and not aimed at the sun but laying horizontally. So your phone would need to sit around outside most of the time to stay charged.

Shake Charged: Have a generated that operates by shaking the phone up and down. This would not be fun, considering that human arms are rarely trained for endurance and can put out dozen watts continuously with training. Imagine jerking your phone for am hour to charge it up, that and a shake generator that could put out 30 watts is going to be large and cumbersome.

[lajoswinkler]

Here are the power sources that could do that

Pu238: Gives off about .5 watts per gram with a half life of over 80 years, a thermal electric converter at 5% efficiency could generate .5 watts (enough to keep a phone charged) with 20 grams. At several thousand dollars gram this would be an expensive phone.

Bio-electric fuel cell: Yeah sure we could make it operate on sugar or ketone bodies from your blood, we would need to install a fuel cell in your body that can produce up to half a watt, operate continuously for years and be medically certified, experimental research has been undertake on animals but I think this one is still many years away.

Solar power: The back of a smart phone has about 0.01 m^2 surface area, a really efficient and expensive GaAs solar panel could do 30% efficiency, faced into the sun it could produced 3 watts, a 3000mAH 3.5V battery can hold about 10 WH and would be charged in 3-4 hours of direct sunlight, perhaps a full day in realistic weather and not aimed at the sun but laying horizontally. So your phone would need to sit around outside most of the time to stay charged.

Shake Charged: Have a generated that operates by shaking the phone up and down. This would not be fun, considering that human arms are rarely trained for endurance and can put out dozen watts continuously with training. Imagine jerking your phone for am hour to charge it up, that and a shake generator that could put out 30 watts is going to be large and cumbersome.

Also:

Pu238: Heat engine is efficient as the heat transfer is. Unless that phone has a large metallic radiator on its back,

it would overheat or at least have lower efficiency than expected. In addition to that, daughter products emit gamma rays which would induce damage, at least to the camera sensor.

Solar power: Getting rid of the heat would be a huge problem. Batteries would quickly die if they were subjected to such stress every day.

Shake charged: Damage to accelerometer and camera focusing mechanism. Possibly this, too.

[Deadpangod3]

Solar panels...

[Idobox]

We want a phone that consumes very little, so smartphones are out of question.

The fabled Nokia 3310 had a standby life of 55 to 260h with a 900mAh 5.2V battery. Let's say 250h with 5Wh battery to get nice round numbers: it gives us an average consumption of 20mW only.

Pu 238 : one gram of plutonium, releasing 500mW of heat, less than an idle smartphone, and with a thermoelectric generator producing 25mW of electricity. Add a battery to store enough energy for calls lasting tens of minutes.

Solar : Assuming a smartphone sized device, and the 3W figure cited previously, 10 minutes a day would be enough to account for stand by consumption. 2h would be enough to fully charge the original Nokia battery, and you remember these things needed to be recharged only once in a blue moon.

Batteries: Li-SOCl2 are stated to have 500Wh/kg energy density. 20mW for 5 years mean 876Wh, and a 1.7kg battery, not even allowing you to actually use your phone.

It would be possible to reduce the consumption even more, by sacrificing functionality. For example, this GSM module consumes 3mW in idle mode, so it should be possible to make a phone that consumes about as much in iddle mode

http://www.u-blox.com/images/downloads/Product_Docs/LEON-G1_ProductSummary_%28UBX-13003277%29.pdf

It means dividing the power, so the amount of Pu, heat loss or battery mass by 7.

Such a phone would need a battery weighing 270g for a 5 year idle lifetime. That's a lot compared to the typical smartphone, but it is quite light compared to a hardened military radio.

And the solar 3W option would be able to run for 1000h (around 40 days) with a 1h charge. Someone please kickstart the Eternal dumbphone of endurance.

[RuBisCO]

Well for the heat from solar you just going to have to have the solar panels be seperated from the phone so the phone body can be kept out of the sun. In fact back in the peace corps this was how we charged our phones and even laptops:

Although they improved the model much since then I was getting half their claimed wattage aimed direct at the sun at noon in cloudless sunlight 5 degress below the equator.

Anyways long story short solar is the best option for a "chargless" phone, actually built on the phone though: skechy. If you want a temperature resistant battery that could be done, but then the battery would always need to be hot (Zerbra cells or Sodium sulfur or any molten salt cell) and that going to require alot of insulation.

Edited June 2, 2014 by RuBisCO

[Javster]

(typically 1-2 years)

Really? My iPhone is over 2 years old, and it's not even damaged or slow

[Alchemist]

You're missing a point. You can't have a nuclear reactor the size of a smartphone battery. You need a pile of the fissionable material, or else you have no criticality.

Of course, let's check how much... 15 kg of U-233??? Yeah, not happening.

Where do people get the idea that Th-232/U-233 will solve everything? It can be a bit better than U-238/Pu-239, but the later at least is a parallel reaction in U-235 reactors that is taken advantage of. Did someone launch "uranium - bad, thorium - good" propaganda? (I actually like the idea of the breeder reactor, because more abundant and cheaper fuel is always better, but some things said about it, as with many of new tech propositions, sound much like "there are much less costs and problems... we are aware of...")

Anyway, if someone makes this as power source for a car I'm not sitting in it. I'm okay with idea of RTG-powered car (at least you can know what it radiates and what is the required shielding), but a fission reactor is something that needs much more protection.

[ThinkOutsideTheHangar]

Plutonium RTG's in my opinion, is the best for phones.

[RuBisCO]

Plutonium RTG's in my opinion, is the best for phones.

No not a good idea for several reasone mentioned, we will need to produce 0.5 watts electric continously for years, an RTG does about 5% efficency so that a 20 Watt heat source.

1. Several thousand dollars a gram, at least 20 grams needed.

2. How to pump out the waste heat, the hot side alone will be above 800C

3. The low levels of neutron emission and gamma rays from daughter product decay and random neutron fission.

[WinkAllKerb'']

TLDR @op like watch that use balancing process and gravity you mean ? or in space too ?

Edited June 2, 2014 by WinkAllKerb''
ooops this is no longer a sci fi thread .....

[rtxoff]

Anybody knows the watches without batteries that charge by the movement of your hand?

Scale up the technology and put it into a mobile phone. Voila. As long as you carry it with you it will get charged by your movement. Sure the phone would be heavy but who cares, it's free energy

Another option: anybody knows the pocket lamps that can be charged by pressing a lever all the time, put that tech into a mobile phone and you can charge it by hand.

Damn i am a genius

[WestAir]

What do the Jedi use to power their lightsabers?

Use that.

[WinkAllKerb'']

stop eat apple gp mr J said it's baaaaaaaaaaaaaaaaaaaaad, you might be strike by a jungle book snake and a tiger wood ... o my *yawn*

Edited June 2, 2014 by WinkAllKerb''
will smith IT in a world of craftwar

[KerikBalm]

Halfnium nuclear isomer powered phone:

http://www.projectrho.com/public_html/rocket/spacegunexotic.php

At the bottom

"One gram of pure hafnium-178m2 (the same mass as a paperclip) contains about 1330 megajoules of energy. This is the equivalent of 317 kilograms of TNT, about the same as the warhead on a Tomahawk cruise missile (TLAM-C). Now you know why people started to talk about a "nuclear hand grenade." (as Alan Bellows puts it: "the most appealing aspect of isomer triggering was its potential to shoehorn yet more death and destruction into convenient 'fun size' packages")

There was also speculation about using hafnium-178m2 as a power source. A suggested application was a nuclear isomer powered airplane. The popular term was "quantum nucleonic reactor".

What was even better is the fact that the energy emerges not as visible light photons, not as ultraviolet photons, not even as x-ray photons. This stuff spits out freaking gamma rays! In other words, it just might be the key to constructing a gamma-ray laser.

The US military was also interested in the fact that hafnium-178m2 could be used to circumvent the Nuclear Non-Proliferation Treaty. Tremendous energy release, intense gamma rays, but it ain't a nuke."

http://en.wikipedia.org/wiki/Nuclear_isomer

[Nuke]

seems there are companies out there trying to bring back betavoltaics.

http://www.widetronix.com/products

they actually have some numbers about what kind of power you can get from their devices. they got a tritium based device you can source a microwatt for 12 years, and a nickel63 device that can source 500 nanowatts for 100 years. you can run a microcontroller with that if it spends most of its time in sleep mode, waking up for a few seconds and then going back to sleep. you might be able to accomplish burst transmissions (a few bytes over a very short period of time), but this wont work for voice communications (maybe text messages, tough you will need to wait for your caps to recharge after each send).

[Skyler4856]

I wonder how hard an aptly sized electrolysis-based power plant would be to develop, simply have it run off of H20 vapor in the near by atmosphere.

[Kryten]

I wonder how hard an aptly sized electrolysis-based power plant would be to develop, simply have it run off of H20 vapor in the near by atmosphere.

It'd be pretty damned hard, given electrolysis of water is endothermic.

[Skyler4856]

It'd be pretty damned hard, given electrolysis of water is endothermic.

You'd burn the by-products... not utilizing the actual reaction, probably should have clarified.

[andrewas]

So your splitting H20 to produce H2 and O2, and then burning the H2 and O2 to get H2O again? You can't produce energy that way.

[Kryten]

You'd burn the by-products... not utilizing the actual reaction, probably should have clarified.

Burning the byproducts gets you exactly back where you started in terms of energy.

[SunJumper]

So you want a phone that doesn't need charging over its lifetime? There is an incredibly easy solution.

Disposable phones! When the phone gets flat, chuck it out!

It would require phones be 90% cheaper, and for all the phones data be stored in the "cloud".

[cantab]

The battery life in current phones could easily be extended hugely. Increase the battery size and radically reduce the power draw of the phone. Never charge might be some years away, but I'd guess a charge a month is plausible.

Of course, that means a heavy, dumb phone. Few people will buy it. People grumble about smartphone battery life, but they'll still pick the fast chip and the bright glossy screen every time. Meanwhile the chip's speed goes to waste running ever more inefficient code, and the display is worse in bright conditions than a matte e-ink display could be.

[K^2]

Not really. It all depends on the fuel. Pu-238 would be the obvious choice if you can make an RTG efficient enough to cram it into a phone, as the alpha particles emitted by it are just normal alpha particles (5.593MeV), and thus have low penetration (skin is enough to block them, easily; the metals in the phone would further reduce their penetration potential).

I've discounted Pu-238 because of it's relatively long half-life and low mass defect. Nothing in 10-20y range is anywhere near as nice. But considering the reductions in necessary shielding, the fact that you'd need about 20g of fuel instead of something like 1g is not a big deal.

So yeah, you are right. One could do this safely with Pu-238. And it'd actually only cost about $1M per phone, which is better than I expected.