Saltwater battery from steel wire and copper foil powers LED

[Dyamios]

What's stopping us from jamming plates of copper and steel in the ocean and running our houses off of that? It seems hard to believe that it would be possible to deplete the entire ocean of its ions 

[hartiberlin]

Well, it could work,
but you would pollute the oceans with lots of copper Chloride
and copper sulfate and the copper and iron electrodes would
get consumed...

But for a test cell this would work quite okay.
As he uses multistranded iron wire the surface of the iron
is much bigger and so he can draw more current,
as if you only take an iron  nail.

[Sunsaver]

I have built and tested several of these types of batteries. The current does not change with surface area in any of my tests, nor with proximity of the electrodes. However, using a strong acid will increase the current and shorten the life of the battery. Another unusual effect is that after the LED light has been on for several hours, it will appear to be burning very dimly. When disconnected, the voltage across the battery is found to be very low. Subsequently, it gradually rises over the next 10 minutes or so, back up to full voltage. When the LED is reconnected, it now shines brightly again. My theory for this self recharging effect is that ionized water molecules are being attracted to the negative electrode (iron) and are blocking the electrolyte therby causing a voltage drop. When the load is removed, the solution returns to a uniform mixture of salt and water (i'm using epsom salts and water) One way to test my theory would be to shake the battery and see if the LED gets bright again. But so far all my batteries have been open jars. Im working on a sealed battery with a tiny vent for out-gassing, so i can test this theory, but if some else out there can explain this strange recharging effect to me i'd love to hear from you. Thanks

[PhiChaser]

... theory for this self recharging effect is that ionized water molecules are being attracted to the negative electrode (iron) and are blocking the electrolyte therby causing a voltage drop. When the load is removed, the solution returns to a uniform mixture of salt and water...

Makes sense to me. Similar to the end of a magnet getting 'saturated' with iron filings...
Would like to hear/see more about your projects!
Cheers!
PC
EDIT: I wonder if the water was moving around your electrodes (instead of sitting stagnant) would prevent the drop in voltage? Have you tried just giving the liquid in your jars a gentle 'swirl' instead of disconnecting the LEDs to bring the voltage back up?

[PhiChaser]

Hey Stefan,
Those videos have been removed by the user.
PC