Urine Powered Battery Developed

Saeed al-Sahaf writes "Research investment into developing smaller and cheaper chips to process information in disposable health tests has been significant, but they were still reliant on an external power source. The researchers at Singapore's Institute of Bioengineering and Nanotechnology think they have overcome this problem with their latest urine powered battery. From the article "The battery is composed of paper, soaked in copper chloride, sandwiched between layers of magnesium and copper. The whole thing, once laminated in plastic, is just a millimeter thick, and 6cm by 3cm in size." The breakthrough promises a cheap and disposable power source for home health tests."

Comments

Why don't we have hand cranks?

[hellomynameisclinton]

Why don't they just give us a hand crank? They're more than efficient to power or charge all sorts of small electronics. All we need is a universal plug interface, and we can all be our own emergency backups.

"Pee in this... and turn this."

While they're at it, why doesn't my car have an emergency gear/wheel/crank system that I can connect ot my battery on cold days when my Jolapy won't start?

Wow

[Murphy Murph]

So, let me get this straight...
It's a battery.
Shipped dry.
Electrolyte added only when needed.
How is this new?

(It's not really urine powered anyway. Urine is just the electrolyte.)

Re:Wow

[Angst Badger]

How is this new?

Near as I can tell, it's new like most everything else is new -- the folks who slept through basic science classes missed how simple galvanic cells work, and now they're surprised by PR from an engineering firm whose employees didn't sleep through science class.

For those just tuning in now, Wikipedia has a nice explanation of this cutting-edge 1780 technology.

For those inclined to experiment, stick a copper rod and an iron rod an inch apart in the dirt in your backyard, and piss in the space between them. Connect wires to the tops of the rods and then to a voltmeter. Wooooeee! You've got current. And you can recharge every time you need to pee.

Of course, technically speaking, you aren't recharging anything. Rechargeable batteries involve a reversible chemical reaction, while a galvanic cell just slowly dissolves its anode and cathode in the intervening electrolyte. For the purpose of providing a feeble current to a disposable medical device, it's not a bad idea. The battery is, however, really old news -- like more than three hundred years old. It's the microelectronics that can take advantage of such weak currents that are the real news, but those aren't exactly at the bleeding edge, either.

Let's do the math...

[Pollux]

The whole thing, once laminated in plastic, is just a millimeter thick, and 6cm by 3cm in size...0.2 millilitres of urine the battery will provide around 1.5 volts, with a maximum power output of 1.5 milli-Watts

So, let's get some facts...Jeeves says that normal humans feel the need to urinate when they hold 150 - 200mL of urine in their bladder. 200mL sounds decent for this math.

200mL / 0.2mL per battery = 1000 batteries that can be charged on a normal fill of urine.

1000 batteries * 1.5 mW per battery = 1.5 W
1000 batteries * 1.5 V per battery = 1500 V
1.5W / 1500V = .001 Amps = 1mA

So, my own piss only has as much power as a spark of static electricity. Sorry folks, but it's going to take more than one run to the toilet to power your laptop.

I'm a bit skeptical

[JourneyExpertApe]

I'm afraid this post will get lost in all of the pee-pee jokes, but what the hell. I don't see what function urine serves in these batteries. I didn't think urine was all that energetic. The article says these things can output a maximum of 1.5 mW at 1.5 V, so why not just use a tiny alkaline battery? A very tiny battery could be produced for a few cents and they have shelf lives of several years. I just don't see why you need to involve urine at all (other than the fact that it gets your research in the news). What am I missing?

Re:Two words: RED DAWN

[Anonymous Coward]

But if the tank is designed to work with a gas, how can it work with a liquid?