Water activated light...no more batteries

[Paul-R]

You should be able to adapt the thinking to aircrafts' ULBs (viz MH370 etc)

https://en.wikipedia.org/wiki/Underwater_locator_beacon

There will be voltage issues but if you can, you'll get on Boeing and Airbus' Christmas card list.

[sm0ky2]

is everybody paying attention??

here you go. This is the list.
Any two elements on this list is a saltwater battery.
the further away from each other they are on the list, the more energy produced.

As logical thinking would lead one to believe, the technology shown above uses graphite (carbon) and Magnesium.

Here is another one, that doesn't try to hide anything from you.
https://www.youtube.com/watch?v=Mw9jS9loVKk

"replacable rods" in the device from the original post are consumed, because the Mg is destroyed in the process. creating magnesium chloride and sodium hydroxide.
This is evident by the "used" water becoming more alkaline. Also, some free chlorine is released.

this was invented by Count Volta back in the 1800's.
Also can be used is U.S. Pennies, to make a voltaic Pile. This contingency was put into place by Ronald Reagan,
as a contingency for a power grid collapse. Some of you may have noticed, pennies are not all copper anymore.
Pennies can be used in emergency to create batteries.
There is a standing Public Service Announcement, in the U.S. that can be sent out over the t.v. and radios that instructs people on how to build these. unfortunately, unless your radios and tvs are battery powered, only a few people will actually get this message, if the grid fails. Even fewer will understand it.

This is simple, 2 different metals, + saltwater.
The results of experiments in this in the 1800's led to the development of the triboelectric series of elements and the electrochemical battery. As well as the invention of electrolysis and the discovery of electromotive force.

[gyulasun]

....
While im here.have you heard anything about a new solar cell that claims an efficiency of 72% ?--this would make a huge change world wide if it is true.
....

Hi Brad,

The 72% efficiency is a combined result of the solar cell and concentrated heat usage at the same time, see this description from 2010:
http://www.greenoptimistic.com/zenithsolar-z20-chp-efficiency-20101020/#.VrywO0CnwqQ
A video from ZenithSolar of Israel:
https://www.youtube.com/watch?v=4izFzVCzx6A

Here is a system that concentrate sunlight by mirrors to get 72% efficiency:
https://www.youtube.com/watch?v=8M-wHBDes-8

Of course, concentrated sunlight by mirrors has the issue of heating up the solar cells, so they need cooling.

Here is an 'official' chart (i.e. confirmed) on solar cell efficiencies to date, (no sunlight concentration),  see the chart in this link:
http://phys.org/news/2016-02-solar-cell-efficiency-nrel.html 

And news on achieving 46% efficiency (direct conversion of sunlight to electricity) by multi-junction cells (this result is included in the above chart):
https://www.ise.fraunhofer.de/en/press-and-media/press-releases/press-releases-2014/new-world-record-for-solar-cell-efficiency-at-46-percent

Gyula

[Nink]

@sm0ky2 thanks for the chart and the info on why they changed the metal on the penny.  I did not realize the penny battery was intentionally created. clever (I wish they only coated one side with copper though so you didn't have to sandpaper the copper off).

[markdansie]

Hi smoKy2
You are right that a combination of any of those two elements and salt water is a battery. This technology is not a battery so to speak except you will consume the anode. It is more like a fuel cell technology and consumes oxygen. The problem with just using two dissimilar metals (which works fine) is energy density. Try an experiment where you put a piece of carbon and say magnesium in salt water. measure the amps across (short) You will see it is high at first then drops to around 20 or 30% of the initial measurement.  The difference with this it will climb much higher with the same piece of metal (whatever you choose for the anode ) and climb to a level many times higher than a  traditional battery.
It is still based on old and well known technology. Thanks for the information
Kind Regards
Mark