Measuring Stratification in 2V Cells

[billi]

Its the compressor that gets hot  or?  so membrane pumps should work better ? http://www.schego.de/membranpumpen.php?lang=en

What plastic pipe would work , when penetrated into the cell ?

When i look at my pond building suppliers website  i should be able to harvest the whole gear for our 2x12 cells including pump for about 60-70 euro   

[knighty]

it's the compressor which gets hot....

I'm not sure if it's through friction or heat from compressing the air.... I guess there'd be hardly any pressure in the system so that will rule that out ?


perfect pump for a test system, just don't plan on using it forever !

I checked mine and it says not to use it for more than 12min in an hour :-o

[stephendv]

Billi, some more info here: http://www.hoppecke.com/products/applications/industrial_trucks/trak_r_air
As I understand it, the pump should be on during bulk and absorb.  The charger just sees a battery that charges faster, no other changes necessary as far as I know.

The Sunny Island has a preprogrammed setting on one of the relays specifically for such a system  

[Eleanor]

Knighty, thanks for tip. I'll keep an eye on it and taking the cover off sounds like a good idea. Even if I have to switch it off and let it cool down (or as you say use a fan) it will hopefully get me the info I want   I'll try not to electrocute myself  

Billi, in this instance it is really only for a few hours to mix up the electrolyte in one cell to prove or disprove that there is stratification so I think most plastic piping would be OK but PTFE would be my choice for a continuous application. I won't be charging at the same time as this would affect the SG and ruin my experiment. The pump is just something we've got available without having to make a four hour round trip or wait for delivery  

After this little episode it is something I'd like to look into more. The only real question I have at the moment is how far I need to put the tube into the electrolyte to make a difference within a reasonable timescale. I suppose the answer will appear when I try ..

I tried googling "2V cell aeration systems" and No 1 on the list was this thread  

[billi]

The Sunny Island has a preprogrammed setting on one of the relays specifically for such a system  Grin

I know      , great product , but i do not like the colour    

just kidding

[stephendv]

I tried googling "2V cell aeration systems" and No 1 on the list was this thread  

Try "electrolyte circulation" instead.  Every manufacturer of traction batteries has one.

[billi]

The pump is just something we've got available without having to make a four hour round trip or wait for delivery 

Perhaps pump up a (tractor) tyre  tube put weight on  and connect it somehow to the cell  and slowly release air  to the cell

[Eleanor]

Stephen, thanks, will give that one a go. Now you've mentioned electrolyte circulation and I've noticed that you said electrolye circulation I wonder if we google electrolyte circulation we'll be at the top of the electrolyte circulation list  

Billi, that's a really good idea  If I go out now I'm sure no one would notice the inner tubes from their tractor tyres had gone and I could just put them back when I've finished with them 

[billi]

do you know what  , my first own car was an old beetle   the windscreen wiper spray "technology "  was attached  to the pumped up spare wheel  valve    in the front boot

[Eleanor]

Dammit, there goes my next good idea. Already been done 

[rogeriko]

Many forklift batteries use electrolyte circulation

http://www.aircontrol.es/documentos/extranet/lm_quattro_batteries_2006.pdf

As you can see the air pipe has to go to the bottom of the cell and it has a protective tube to stop the bubbles damaging the soft lead plates.

[johnrae]

[quote

As you can see the air pipe has to go to the bottom of the cell and it has a protective tube to stop the bubbles damaging the soft lead plates.
[/quote]

Actually its an "air lift pump" arrangement.  The air bubbles issuing out of the bottom of the inner tube rise up through the outer tube and in doing so push liquid up between each bubble to exit at the top  of the outer tube.  Too much air inhibits to process.  The outer tube must be an inch or so lower than the air tube to prevent the bubbles escaping out of the outer tube bottom.

jack

[Justme]

For air pumps & air lift tubes check out aquarium suppliers.

Low power long run pumps for sensible money.

[Eleanor]

Aquarium pump - back to what I said in my original post then!

I've pretty much lost confidence in this working and producing anything useful as I'm not prepared to prod around in the cells and probably won't be brave enough to use a sufficiently high flow rate to stir it up. If the cells weren't under warranty I'd give it a go. Anyway, I've got this far so I may as well persevere with a test not involving the cells and see what happens. I've found a few bits and pieces lying around which could be useful :

Pics 1 and 2 : Dripper system purchased in sale for £10/box. Manifolds, valves, T-pieces ... Not intended for air use of course .. Will probably need a bigger tube as well to prevent backpressure on the pump and the drippy bits will have to go.

Pic 3 Test vessel - or bucket to the less informed. The more observant amongst you will notice the vital piece of equipment to the right of the picture 

Pic 4 : Piece of above dripper tubing languishing in sulphuric acid in my best stainless measuring jug.

This is supposed to be a quick test to prove that some of the cells in our battery bank are not suffering from long term stratification and possibly resultant sulphation due to undercharging. It is not intended to be a permanent set up.  

At least the bucket of water will be handy for sticking my head in 

[Eleanor]

Pics 3 & 4