## Bio Battery

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fortis.e.a.lex
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### Bio Battery

Ok, i just calculated something real fast and was suprised by the answer and was wondering if i did something wrong.

We have something like 50E18 cells in our body, each one of them as mitochondria that generate an electro motive force of 0.2 V to create ATP via the ATP synthase... so if we could use all those "battery" and connect them together (wich is imposible) we could get a battery of 10 exavolt wich is something like 10 billions times greater then lightning... no?

thoughtfully
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### Re: Bio Battery

If you were somehow able to connect them all series, yeah, why not? You probably wouldn't have a high current, though.

Anyway, anything's possible with a sufficiently improbable if being satisfied
Last edited by thoughtfully on Wed Feb 02, 2011 11:17 am UTC, edited 1 time in total.

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Meteorswarm
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### Re: Bio Battery

Of course, connecting them in series would probably involve nesting all of them inside one another.
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Tass
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### Re: Bio Battery

Also 5*1019 times a membrane thickness of 5nm makes 2.5*1011m or more than the distance from the sun to Mars.

Wildhound
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### Re: Bio Battery

Also, wouldn't we need to feed them?
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p1t1o
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### Re: Bio Battery

5*e19 sounds like an awful lot, I've heard it quoted a few times but always in between 50 and 100 trillion, or 0.5-1.0*e14

idobox
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### Re: Bio Battery

Meteorswarm wrote:Of course, connecting them in series would probably involve nesting all of them inside one another.

You don't really need to nest them. Put them in different culture media, and put a saline bridge between the inside of one and the outside of the next one. Easy
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Moose Hole
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### Re: Bio Battery

You could make a vast computer simulation so that they think they're living in the late 20th century while we're harvesting their energy.

Izawwlgood
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### Re: Bio Battery

You just played Parasite Eve didn't you?
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Technical Ben
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### Re: Bio Battery

Would it be comparable to trying to get thousands of ants onto a conveyor belt to generate electricity from their walking?
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KittenKaboodle
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### Re: Bio Battery

Technical Ben wrote:Would it be comparable to trying to get thousands of ants onto a conveyor belt to generate electricity from their walking?

That's really clever, , but no, thousands of ants on a treadmill could actualy "work" wouldn't really be practical, but it imagine it is many orders of magnitude less impractical than trying to put a bazilion biological cells in series.

Somewhat more practical would be to connect 150 billion drycells ( http://www.japancorp.net/article.asp?Art_ID=23371 ) in series ~ 225 billion volts and not totaly insignificant current. But I suppose that is straying a long ways from the OT as it would be a bit larger than one human, I imagine that the oringanl point was that the huge number came form doing creative math with one human body.
Wikipedia wrote: an EPFCG package that could be easily carried by a person can produce pulses in the millions of amperes and tens of terawatts, exceeding the power of a lightning strike by orders of magnitude.[citation needed]

Fun things one can do when comparing voltage, current or power while ignoring energy, Wikipedia says average lightning bolt ~ 500MJ, TNT ~4.7MJ/kg, I suppose I could carry 100 kg for a short time, but there is also a lot of copper in a EPFCG.

also; http://xkcd.com/651/

Izawwlgood
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### Re: Bio Battery

Technical Ben wrote:Would it be comparable to trying to get thousands of ants onto a conveyor belt to generate electricity from their walking?

Muscle contraction can be described with a similar metaphor. Just sayin'.
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p1t1o
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### Re: Bio Battery

What is the point in haveing a source of huge voltage if it can only supply a tiny current? Is it not like manufacturing a battery with a built in resistor?

Technical Ben
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### Re: Bio Battery

Would the device survive it's own activation? Or would it be one time only? Do those things even burn out anyway?
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gmalivuk
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### Re: Bio Battery

p1t1o wrote:What is the point in having a source of huge voltage if it can only supply a tiny current?
Whatever the point may be, it definitely would be a tiny tiny current.

First of all, we only have about 1e14 cells, so the OP was already off by 5 orders of magnitude. But at 0.2 V apiece, this still gives the not insignificant potential difference of 2e13 V. Of course, since the human body runs at about 100 W, that amounts to a current of only 5e-12 A. Good luck doing anything with 5 picoamps.
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Technical Ben
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### Re: Bio Battery

gmalivuk wrote: Of course, since the human body runs at about 100 W

Never knew that. Adding it to my list of useless (almost) knowledge.
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thoughtfully
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### Re: Bio Battery

That's the heat generated, and how many calories per day. I'm not sure what it has to do with any electrical properties of the body.

I've known this rule of thumb a long time, but I recently did the calculation of 2000 calories in 86400 seconds, and it really is damn good rule of thumb: almost 97 watts. The 2000 calories a day thing is already a rough rule of thumb, though. I tried to search for a more precise average figure, but the real recommendations are a fairly complicated function of sex, age, and activity level, so I gave up on that idea.

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gmalivuk
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### Re: Bio Battery

The basal metabolic rate is fairly simple, in that even if you can't memorize the two equations you can go to hundreds of different websites that will calculate it for you. (For example, I know that my basal rate averages to about 105 watts because I'm heavier than average and thus require more calories just for basic bodily maintenance and heat generation.)

thoughtfully wrote:That's the heat generated, and how many calories per day. I'm not sure what it has to do with any electrical properties of the body.
The electrical property under discussion is that used to create ATP, which is how the body gets energy from the food that it eats. Granted, there's obviously more energy stored in the ATP than is used to create it, or else this system would never have evolved. So 100W is actually a really generous upper bound for figuring out the amount of current involved in each of those 0.2 V potential differences.

And while perhaps current is a roundabout way of thinking of it, if there's not actually current flowing through that potential difference, but the 100W figure also tells us about the total stored energy. A Volt is 1 Joule/Coulomb, and an ampere is 1 Coulomb/second, while Watts are Joules/second. So given some particular length of time, we can figure out the maximum amount of energy ever stored in those little potential differences, and from there compute that this "battery" would hold a laughably tiny amount of charge.

(For comparison, AA batteries typically hold a couple amp-hours of charge. If the OP's battery, running on several times more than mitochondria usually would, could only produce 5 picoamps of current, it'd need to run for about a trillion hours (over 100 million years) before it had provided the same total amount of charge as a single cheap AA.)
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Meteorswarm
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### Re: Bio Battery

gmalivuk wrote:Granted, there's obviously more energy stored in the ATP than is used to create it, or else this system would never have evolved.

I might be misreading you, but ATP definitely holds less energy than the food used to create it; it's a basic rule of thermodynamics.

Your overall point is correct, though. The maximum sustained power output of a Human is something like 100 watts, and even if you magically converted that to electric current via whatever scheme you can dream up, it's still 100 watts. P=IV.
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gmalivuk
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### Re: Bio Battery

Meteorswarm wrote:
gmalivuk wrote:Granted, there's obviously more energy stored in the ATP than is used to create it, or else this system would never have evolved.
I might be misreading you, but ATP definitely holds less energy than the food used to create it; it's a basic rule of thermodynamics.
Yeah, what I meant to say was that not *all* 100W of food power could be flowing through the 0.2V potential differences, because some has to be left over for the ATP. But even that is obviously wrong, because all the energy *any* electricity ever provides had to be flowing as current at some point.

Still, 100W remains the upper bound on the average total power that could ever be transferred across those potential differences, on account of that being the average total power that's available at all to bodily processes.
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Wildhound
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### Re: Bio Battery

gmalivuk wrote:
Meteorswarm wrote:
gmalivuk wrote:Still, 100W remains the upper bound on the average total power that could ever be transferred across those potential differences, on account of that being the average total power that's available at all to bodily processes.

I don't think this is quite correct. Feel free to point out if there's a problem with my logic here.

100W is an average figure for a human at rest (within reason anyway, that would obviously include some moving around such as walking to the bus stop to get to work, or even to the fridge to get dinner), but an active human can go way above this. For example, if I were fit enough I could cycle 100km in a day and, if I pushed myself hard enough, burn 2000 calories through that process alone. My average power output for that day would then approach 200W.
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gmalivuk
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### Re: Bio Battery

By total average I meant long-term.

But of course, since the discussion about current initially started with wondering how much would fry the battery, you're right that we should look at maximum power output rather than long-term average, which is probably closer to 500 or even 1000 Watts.

So we're maybe up to 50 picoamperes instead of only 5!
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Wildhound
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### Re: Bio Battery

Yeah, 50 picoamps at 20TV might be useful for something. Just don't ask me what that might be.
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p1t1o
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### Re: Bio Battery

The solar system's very own digital watch? With designer wristband? Exactly what time would you set it to?

Velifer
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### Re: Bio Battery

So we should just take some of this biological material and set it on fire, then we could use it to make steam, and spin a turbine, hook it up to some windings and a magnet and... Oh YEAH! Off to the patent office!

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