Working Air Battery

[lasersaber]

@capthook

Thanks for sharing your thoughts.  None of the points you mentioned really matter for the applications I have in mind.  Here are some things to consider.

1 - Not everyone in this world has access to the grid.
2 - The Magnesium ribbon I am using can be bought easily for $3.50 a roll.  It may be even less in bulk from other sources.
3 - I think this same design could be built using aluminum and other metals.
4 - The carbon rod could also be a hollow tube design that would use at least 75% less carbon.
5 - They may very well last much longer than you are predicting.

I have two tests projects running at my house now that I will leave running until they stop.  This will give us some idea on how long they will last.  I have a motor running off a very small air battery and the flashlight connected to two large air batteries seen in my last YouTube video.  I will run them with out wetting them down and under constant load and see how long until they stop.

I have a dream of getting these perfected and making something like the Oxford Electric Bell: http://en.wikipedia.org/wiki/Oxford_Electric_Bell  I think having an electric motor that runs for years on end with no up keep would be very cool.  I think I may have already have this worked out but the only way to know is more long term testing.

[capthook]

1 - Not everyone in this world has access to the grid.
2 - The Magnesium ribbon I am using can be bought easily for $3.50 a roll.  It may be even less in bulk from other sources.
3 - I think this same design could be built using aluminum and other metals.
4 - The carbon rod could also be a hollow tube design that would use at least 75% less carbon.

I hope you folks don't think I'm saying there is no value to what is being discussed/examined here.
The idea of creating electricity from 'simple' items and in a 'simple' way is great.
Just wanted to give some numbers/math/costs etc. for all to see/use for a better evaluation.

To your points:

1 - Those without grid access tend to be in extremely poor areas so $/watt becomes even more important.
Solar/sun is available everywhere and the current benchmark of $1/watt from First Solar is hard to beat.
To cut the cost of the current airbattery by 1/2 is still $17/1.5W = $11/watt.
3 - Aluminum will probably see a reduction in output but result in production at a much lower $/watt.
4 - Excellent!  To expand on that idea, a 2nd layer of anodic material (aluminum) could be added to the interior of the tube, increasing output per cubic meter by 2x.  And the reduced graphite content would greatly reduce costs.  However, such a design would require speciality fabrication at increased initial tooling costs.

And for portable applications, watt/kg needs to be maximized.

From a chart (attached) in one of conradelektro's links (A for those links conradelektro), it shows graphite as the best cathode material and magnesium as the best anode materials.
The power you are producing is good @ ~ 2 amps and is undoubtly a direct result of using these materials.
However, the trade-off between output/size/weight/cost may favor materials like stainless steel and aluminium.

I really like your idea #4 - modifying the carbon rods.
The possibility of a 75% reduction weight/cost while increasing output by 2x.

[capthook]

@capthook
Thanks for sharing your thoughts.  None of the points you mentioned really matter for the applications I have in mind.

Ahem...
1) $/watt is of primary importance and matters to *all* applications
2) wh/kg is of primary importance for *portable* applications

[lasersaber]

Ahem...
1) $/watt is of primary importance and matters to *all* applications
2) wh/kg is of primary importance for *portable* applications

If you are looking for someone to argue with you will find that I am much more interested in building things than discussing in theory whether or not they will work.

[jeanna]

Well, well, well,
I spent most of the morning researching magnesium stone (magnesite and bruxite) and sourcing magnesium so it could be used as a fuel cell. I do not know how to do that, but it seemed the right material.
I finished all I could do, then came here, and I am so glad you put those links up.

How do we find magnesium plates?
@pete,
Did you give us the details of the broken carbon rod thing?
It looks small and tidy, but I want details like how much of each material, please?

@conrad,
I will study that post more. I did not realize that cell has done so well.
All mine immediately ate through the electrodes which were Aluminum.
(of course they were making H2 gas with the aluminum)

@lasersaber,
Thanks for all your sharing.
It really helps.

The 5 inch broken carbon (welding) rod and 1.6gr mag ribbon battery I made a week ago started up after I opened the tape to allow some moisture in to the cloth, and it has been running a joule thief (for 14 hours) since yesterday.

thank you,

jeanna