If your iPhone were powered by...

http://graphics.wsj.com/iphone-battery/

by mizzao • 11 years ago

13 11 11 years ago

graphics.wsj.com

fasteo• 11 years ago

>> An iPhone powered by body fat could last...9 days

This only shows how extremely efficient our body is. We can survive without food - with water though - for maybe 40-60 days depending how much fat you carry.

gene-h2• 11 years ago

Or how energy dense fat is if you ignore the conversion efficiency. For this calculation they also assume the whole volume of the battery is filled with fat.

Humans actually aren't that efficient in terms of conversion of chemical energy to mechanical work. Muscle is about 14-27% efficient at converting chemical energy to work, which is about as good as a combustion heat engine.

Now in terms of motion planning, image recognition, and "cognition," humans tend to be more energy efficient than machines.

SixSigma3• 11 years ago

Your body is radiating 1kw too.

thecabinet• 11 years ago

More like 100W: 2000 Calories is 2000000 calories is 8,400,000 Joules. Divided by a day is 97W.

gene-h2• 11 years ago

of course, they are completely ignoring the conversion efficiency of the fuel sources to electricity.

Let's take diesel for instance, conversion efficiency of chemical energy to work for small engines can be about 30% at best, so a much more reasonable estimate for regular use is about 2.85 days rather than 9.5.

Now the interesting thing is that people have actually proposed using internal combustion engines and fuel as a replacement for batteries in electronic gadgets. to do so one uses tiny turbines micromachined using the same techniques to make microchips. One researcher working on this technology estimates that at max an energy density of 1500 Wh/l could be achieved, which gets us a whopping 1.33 days of run time at regular use! http://thefutureofthings.com/3063-engine-on-a-chip/

arcticbull• 11 years ago

Looks like Diesel engines have a thermal efficiency of up to 51.7% [1] (with a theoretical maximum of 56% [2], and Toyota claiming a practical 38% [3]) and Gasoline engines ~25%. Based on that, a Diesel powered phone would last 3.8-5.6 days.

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

[2] http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/diesel.htm...

[3] http://www.greencarreports.com/news/1091436_toyota-gasoline-...

Const-me• 11 years ago

Nah, don’t believe it has the future. Even gas turbines are too unreliable due to temperature and mechanic stress. Fortunately, diesel-powered fuel cells are already on the horizon: http://spectrum.ieee.org/energywise/energy/fossil-fuels/dies...

As you see, they promise efficiency much higher than your 30%.

SixSigma3• 11 years ago

Tbh there is no Moore's law for anything in the way it is implied in the paragraph.

RizlaPleaseLa• 11 years ago

What about uranium?

nacs• 11 years ago

And antimatter.

If your iPhone were powered by...

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