Nothing extraordinary, nor new. Uses zinc and graphite in saltwater.

1.- How is the voltage generated determined/predicted ?

Is it by looking at a galvanic table like ----> http://l-36.com/corrosion.php
Where graphite is +0.25 V and zinc is -1V; yielding as answer a differential of 1.25V ,

Or, should this electrochemical series table be the one to look up ? ----> http://www.chemistry-assignment.com/wp-content/uploads/2013/02/1189.png
And why is carbon not listed there, to attempt reading a differential ?

or is there another method ?

2.- To turn white LEDs on; there has to be a circuit to convert the voltage to near 4V, am I right ?

It is commonly available as ----> https://duckduckgo.com/?q=salt+water+lamp&t=canonical&iax=1&ia=images

3.- Does this mean that using aluminium and stainless steel would yield about the same voltage ?

----> http://xapps.xyleminc.com/Crest.Grindex/help/grindex/contents/corrosionMetal4_files/c03_2.jpg

 

hi Ex.
Look at this link.
https://books.google.co.uk/books?id=q58IX4BM7-0C&pg=SL7-PA53&lpg=SL7-PA53&dq=sea+water+lifejacket+battery&source=bl&ots=lR_rkbIf5u&sig=FWM-RIh6HAnKJr50sp8-wnXEWZo&hl=en&sa=X&ved=0ahUKEwjMzK7Wi9jSAhUCIsAKHV5LDjA4ChDoAQg1MAA#v=onepage&q=sea water lifejacket battery&f=false

I used to design sea water activated batteries for civil and military use, there are loads of different sea water technologies.
E

 

Thanks. The book is not viewable. The attachment does not address 1, 2, 3.
With your knowledge, explaining these doubts should be quick and simple.