Cookies-law

Cookies help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
http://www.overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please leave this website now. Many thanks for your understanding.
Amazon Warehouse Deals ! Now even more Deep Discounts ! Check out these great prices on slightly used or just opened once only items.I always buy my gadgets via these great Warehouse deals ! Highly recommended ! Many thanks for supporting OverUnity.com this way.

FireMatch

FireMatch

CCKnife

CCKnife

Poplamp

poplamp

CCTool

CCTool

LEDTVforSale

Magpi Magazine

Magpi Magazine Free Rasberry Pi Magazine

Battery Recondition

Battery Recondition

OverUnity Book

overunity principles book

Arduino

Ultracaps

YT Subscribe

Gravity Machines

Tesla-Ebook

Magnet Secrets

Lindemann Video

Navigation

Products

Statistics

  • *Total Members: 82004
  • *Latest: jolyon

  • *Total Posts: 493033
  • *Total Topics: 14497
  • *Online Today: 44
  • *Most Online: 103
(December 19, 2006, 11:27:19 PM)
  • *Users: 0
  • *Guests: 55
  • *Total: 55

Facebook

Author Topic: Large Salt water battery ideas and questions  (Read 36606 times)

Offline Mungo

  • Newbie
  • *
  • Posts: 32
Large Salt water battery ideas and questions
« on: July 26, 2013, 01:41:37 AM »
So here is the basic project:  My wife and I have been working on a moderately large houseboat which we intend to move aboard early next year.  A large portion of the  motivation is reducing and taking control of our energy usage.  Accordingly, the original idea was to utilize solar charged deep cycle batteries with a generator backup to drive a paddle (stern) wheel and to provide general power to the vessel.  But recently I've come across information on large salt water cells, and the prospect of using one or two pretty large battery wells to provide power, replacing the electrodes and flushing out the electrolyte with new seawater as needed has become interesting.  So here's the concept we're playing with, and I'd love any ideas, comments, or information the community could provide:

As an aside I should say I am aware of much of the youtube content on such matters, as well as of the Enviro-Gen 12 emergency battery system.

The area I have to play with would create two battery wells, each 16" X 12" X 30", divided into cells (probably 15 from the information I've been able to glean regarding salt water batteries).  The flooded plates would measure at least 12X10", copper and zinc.  Now I'm sure that there is some formula somewhere that would show how much current and voltage such a cell would create, but I've been unable to find said.  It would be possible to create a continuous isolated flow of electrolyte through the batteries.  The salt content would run between 20 and 30 PPT, but that could be amended to a higher concentration.

The motor we were considering creates about 5 hp from 12 volts, geared down 225/1 and series wound.  (I got this idea from some folks building small electric sternwheelers using wench motors as they are already 12 volt and include reliable planetary gearing.)  The batteries would also need to run a modicum of marine electronics and some LED lighting.

Ideas?  Comments?  Anyone able to calculate the likely output?

M

« Last Edit: July 26, 2013, 03:34:37 PM by Mungo »

Free Energy | searching for free energy and discussing free energy


Offline Mungo

  • Newbie
  • *
  • Posts: 32
Re: Large Salt water battery ideas and questions
« Reply #1 on: July 30, 2013, 07:17:50 PM »
To add a bit of additional information, Seawater has a specific gravity of about 1.028 (though it varies depending on the place measured).


Offline profitis

  • Hero Member
  • *****
  • Posts: 3897
Re: Large Salt water battery ideas and questions
« Reply #2 on: July 30, 2013, 10:54:05 PM »
you might want to try magnesium plates instead of zinc and graphite instead of copper.it will pack much more power and last longer.

Offline Mungo

  • Newbie
  • *
  • Posts: 32
Re: Large Salt water battery ideas and questions
« Reply #3 on: July 30, 2013, 11:26:06 PM »
probably an excellent idea.  Im a little concerned, though, about availability.  This is rather on the lines of a "big dumb battery" concept.  Any idea for good sources for magnesium and graphite plates?


Offline profitis

  • Hero Member
  • *****
  • Posts: 3897
Re: Large Salt water battery ideas and questions
« Reply #4 on: July 31, 2013, 02:54:33 AM »
printing plates,old used ones from any print shop should do fine.otherwize aluminum might be a less better but easier option,parts of a ladder perhaps or thick foil roll.graphite can be cut to size plates by order from industrial suppliers of graphite products.do tests on small scale first by removing carbon rods from zinc batteries(non-alkaline ones,cheapo,s,its safe)and rinse and then heat the rods on your stove hotplate or over flame to evaporate all wax binder inside the rod and then it becomes non-waterproof and excellent for tests as a cathode(+).

Free Energy | searching for free energy and discussing free energy

Re: Large Salt water battery ideas and questions
« Reply #4 on: July 31, 2013, 02:54:33 AM »
Sponsored links:




Offline profitis

  • Hero Member
  • *****
  • Posts: 3897
Re: Large Salt water battery ideas and questions
« Reply #5 on: July 31, 2013, 02:57:35 AM »
i forgot,welding suppliers sell large carbon arc-rods by the dozen..

Offline Mungo

  • Newbie
  • *
  • Posts: 32
Re: Large Salt water battery ideas and questions
« Reply #6 on: July 31, 2013, 06:03:50 AM »
oooOOoooh I had forgotten about welding rods.  Thanks...also arclight rods are probably still available.

Free Energy | searching for free energy and discussing free energy

Re: Large Salt water battery ideas and questions
« Reply #6 on: July 31, 2013, 06:03:50 AM »
Sponsored links:




Offline conradelektro

  • Hero Member
  • *****
  • Posts: 1553
Re: Large Salt water battery ideas and questions
« Reply #7 on: July 31, 2013, 09:59:19 AM »
I did many experiments with salt water batteries.

Copper, aluminium, steel and carbon just do not give enough power to make it worth while. The reaction also stops pretty soon due to deposits on the surface of the metals.

Magnesium works better, but is expensive and kind of dangerous in larger quantities (fire hazard, toxic reactions). Also, a magnesium salt water battery (with carbon as the other pole) does in no way compare to a standard 12 V battery, it just can not come near it regarding the power output.

There is a reason why salt water batteries are not used, they do not work well.

The best option on a boat:

Fife to ten 100 Ah 12 V batteries charged by solar cells and a small wind generator. That really works.

http://www.emarineinc.com/pages/Wind-Generator-vs-Solar-Panels-Which-is-Better-For-Your-Boat.html

Greetings, Conrad

Offline profitis

  • Hero Member
  • *****
  • Posts: 3897
Re: Large Salt water battery ideas and questions
« Reply #8 on: July 31, 2013, 01:46:20 PM »
@conrad,there is no reason why a saltbat wont be practical if its done using right materials.just gota test on smal-scale until you get it right.if its porous carbon then it will function as an air electrode and pull more power.aluminum responds well to chloride ion activity.

Offline Poit

  • Sr. Member
  • ****
  • Posts: 295
Re: Large Salt water battery ideas and questions
« Reply #9 on: July 31, 2013, 02:42:19 PM »
What you want is a bank of Nickel-iron batteries... will live longer than you!

http://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery

Free Energy | searching for free energy and discussing free energy

Re: Large Salt water battery ideas and questions
« Reply #9 on: July 31, 2013, 02:42:19 PM »
Sponsored links:




Offline Mungo

  • Newbie
  • *
  • Posts: 32
Re: Large Salt water battery ideas and questions
« Reply #10 on: July 31, 2013, 04:39:41 PM »
Here's my problem with some of the suggestions thus far, at least for this project (and I do thank you all for the input, it has really caused me to think):  :o I'm well aware I could make this happen using conventional deep cycle batteries and a solar or wind charging input and a generator backup.  That's expensive and relies on a lot of outside materials and devices, but it would work just fine.  My question was whether or not a large "dumb" battery, using fairly inexpensive, common ingredients could be made to work for this, given that the power requirements are limited (ie: no refrigeration, no ac, and only occasional use of a series wound dc motor for power, the rest being led lightiing and a modicum of marine electronics).  I would like to avoid things that are exotic or highly toxic, even if those elements were more effective. 

The vessel we're working on is a 42X12 houseboat, and can certainly take quite a bit of weight as long as it's along the centerline.

So given that, what would be required to make this project work, and how might I best do a testbed to find that one out.?

 

Offline Mungo

  • Newbie
  • *
  • Posts: 32
Re: Large Salt water battery ideas and questions
« Reply #11 on: July 31, 2013, 04:46:17 PM »
I did many experiments with salt water batteries.

Copper, aluminium, steel and carbon just do not give enough power to make it worth while. The reaction also stops pretty soon due to deposits on the surface of the metals.

Magnesium works better, but is expensive and kind of dangerous in larger quantities (fire hazard, toxic reactions). Also, a magnesium salt water battery (with carbon as the other pole) does in no way compare to a standard 12 V battery, it just can not come near it regarding the power output.


Thanks for the comment, Conrad.  A couple of questions:  What is"pretty soon"?  With no generator to mess with and no other batteries to service, I've no problem doing maint. on this system every 5-10 hours or so if all i'm doing is wiping off a few plates and changing out the electrolyte.  I'm not demanding lithium cell convenience here, nor it's performance.  If this thing is the size of a kitchen table and takes a daily regimen of low level maint. to keep it running, that's fine.



Offline SeaMonkey

  • Hero Member
  • *****
  • Posts: 1236
Re: Large Salt water battery ideas and questions
« Reply #12 on: August 12, 2013, 08:39:34 AM »
Salt Water Cells using Carbon and Aluminum
do work reasonably well but generate quite
a lot of hydrogen as the chemical reaction
takes place.  Once assembled they like to be
used full time; if they sit idle the aluminum
is slowly eaten away and wasted.

The hydrogen isn't necessarily a hazard but
it does cause "polarization" in the cells which
reduces their electrical output until the bubbles
are swished away from the positive plates.

You may want to try a small scale version of your
battery on a tabletop using small jars to contain
the cells.  You'll probably need to make the salt
solution somewhat more concentrated than sea
water to get the power you are seeking from a
rather small set of cells.

In any case let us know what you discover as you
experiment.

Offline Mungo

  • Newbie
  • *
  • Posts: 32
Re: Large Salt water battery ideas and questions
« Reply #13 on: August 12, 2013, 04:38:14 PM »
SeaMonkey I actually just completed such an experiment, and was able to pull three volts + from six cells, lighting an LED for several hours.  The hydrogen buildup you described was noted, and did indeed affect output (all I had to do was shake the cathode a little and the cell output would bounce back up).  I ran the salt solution at 1.030 sg , a bit above ocean water in concentration (btw for anyone doing this, one great cheap hydrometer solution is to hit a pet store that deals in tropical fish.  Hydrometers for measuring salt concentration in aquariums can be had for $8-12.)

I ran the experiment with both copper and carbon cathodes, and with both zinc and aluminum anodes.  The best reaction I got was with the copper/zinc arrangement, but I suspect that the quality of my electrodes had a great deal to do with that.  I'm having trouble finding a decent carbon electrode at an affordable price (here suggestions, especially for the final project, would b appreciated).  Copper and Zinc are much more readily available, especially in clad form.  The aluminum came from a can, sanded free of its coatings, but rather thin.  In general, I was getting .6-.73 volts from each cell, though the metallurgical purity of ALL of my electrodes is, to say the least, suspect.  I did not, at this stage, attempt to measure current, but the cells did light a 3V white led to full luminance for several hours.

As this is technically an aluminium-air or zinc-air battery, its likely that production finally stopped when the O2 in the solution was exhausted.  Vigorous stirring or the addition of a little hydrogen peroxide kicked the battery back to life (oddly, I remember an old Gilligan's Island in which the Professor did just this to charge their radio batteries, probably with galvanized nails and pennies
; the stirring thing I mean, not the peroxide).

Which brings me to some potential solutions, and I'd love to hear what folks thought of them.  A larger cathode, certainly, would make for less impact of the hydrogen bubbles, but two other options occurred to me.  One was to attach some kind of vibrator to the cathode rack which would steadily or periodically shake the hydrogen bubbles free.  The second, which might kill two birds with one stone, might be to place an airstone in each cell (the bubblers you see in aquariums).  The bubble stream could act to dislodge the hydrogen bubbles on the cathode, and would also serve to oxygenate the electrolyte.  Such air pumps consume tiny amounts of energy(about 2-3 watts at 110V), and other, non electrical means could be used to pump air into this system.

The next, pragmatic phase of this experiment will be to actually build a battery of cells at near full size (probably, given the voltage produced, around 20 cells)to produce 12v dc, and place a load on the system (Im contemplating an inverter and a small electric fan (35w ), along with any shaker or air pump used).  Your suggestions for electrode materials and where to find them would be most helpful, bearing in mind the parameters of the original experiment:  Common materials, easily accessed and replaced, and inexpensive. This whole contraption will have to wait until my next check as it is :)

I thank you all in advance for your comments and suggestions.  This board has been an immense education for me, and I wanted you all to know you were appreciated :)




Offline Mungo

  • Newbie
  • *
  • Posts: 32
Re: Large Salt water battery ideas and questions
« Reply #14 on: August 12, 2013, 07:19:54 PM »
and while Im on this subject, what might be methods for increasing the current in this setup?  I know just increasing electrode size (or running another battery of cells in parallel) would work, but I was curious what other methods might offer themselves?

Free Energy | searching for free energy and discussing free energy

Re: Large Salt water battery ideas and questions
« Reply #14 on: August 12, 2013, 07:19:54 PM »

 

Share this topic to your favourite Social and Bookmark site

Please SHARE this topic at: