# Distill/deionise you own battery-water?



## jockepocke (Nov 24, 2009)

I have been thinking about building a small and simple distillation machine to make my own de-ionised water for my FLAs. I have some e-flasks and other equipment. The process is simple, I will boil the tap water and cool the steam and collect it in another container. 

My questions are: Anyone attempting this before? 

How can I check the ion-content of the water, and what values are acceptable? I do not plan to destroy batteries by using water that is not pure enough...

Any more efficient ways of deionising water (that I can build at home)? (I know that they use some kind of ion filter in my chemistry class.)


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## jockepocke (Nov 24, 2009)

Can I just use the multimeter and metal sheets with a fixed distance of eg. 1 cm to measure the resistance/conductivity of the water?


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## EVMAN (Jul 26, 2007)

Distilled water and DeIonized(DI) water are two different liquids.

DI water can have a resistivity of 15MegOhm.
(i work with it everyday)

Distilled water doesn't even come close on resistivity.

DI water is made (usually) by reverse-osmosis.

T


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## jockepocke (Nov 24, 2009)

EVMAN said:


> Distilled water and DeIonized(DI) water are two different liquids.
> 
> DI water can have a resistivity of 15MegOhm.
> (i work with it everyday)
> ...


I am not sure what you mean when saying that distilled water does not come close on resistivity, do you mean far less resistance, or far more? 


I know of the differences and, according to my chemistry teacher, distilled water should neither contain any ions. I am not sure, however, if you can use deionized water in the batteries... Can you, seeing that de-ionizing does not necessarily remove uncharged molecules?


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## EVMAN (Jul 26, 2007)

Distilled water is around 2MegOhm. Works fine for floodies!!! 
I work in a class100 cleanroom and we make our own DI water for the processes. DI water also works fine for floodies!! 

DI water is made by forcing water thru resin filters. This removes EVERY ion. 
The filters need to be changed after they get clogged.
They are "rejuvinated" and reused again. Not by us; by a contractor.
Google DI water for more general info........

Distilled water is made by evaporation.
There are ALWAYS some minerals (minute quantities) still in the water.
That's why it can't be used in cleanrooms.
The electrolyte impurities are (one of the things) that kill batteries.
Making your own will take energy to evaporate the water, 
then more energy to condense it. U should also have a water conductivity meter. Conductivity is the OPPOSITE of resistivity. 
Resistivity is measured in ohms. 
What do U think conductivity is measured in?? 
A: "mhos"'. Look it up!!!!!!


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## jockepocke (Nov 24, 2009)

EVMAN said:


> Distilled water is around 2MegOhm. Works fine for floodies!!!
> I work in a class100 cleanroom and we make our own DI water for the processes. DI water also works fine for floodies!!
> 
> DI water is made by forcing water thru resin filters. This removes EVERY ion.
> ...


I have already read a bit about DI on wikipedia (actually before I posted), and I could not find any deionizing process for home-use! (Or I could use thousands of cell-membranes!  ) I have forgotten the unit for conductivity, but it is reversely proportional to resistance: conductivity = 1/Ω And when you say the conductivity of distilled water is 2MΩ I guess you mean per cm? 

But if distilled water is resistive enough I will use that, if I manage to produce larger amounts of course. I will measure the distilled water I have at home also, to compare the resistivity. Seems stupid to kill your batteries trying to save money... 

You are right that evaporating the water will require energy (this is simplest solved by using an electric heater such as a waterboiler I reckon), but condensing water releases energy, I do not need any energy input here! Or do you mean for a cooling system? The amounts I will produce should not require more cooling than air or a simple water cooling system could provide. Fans or pump motors should not require much energy at all compared to the heating. And as it is still cold outside the heat will not be completely wasted either!


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## jockepocke (Nov 24, 2009)

I have just set up the trial equipment for distillation. Seems to work good now that the fan is installed. A bit slow though... 










I also calculated energy needed, and I figured I should pay about 1 SEK (0,14 $) per liter. That is way cheaper than buying distilled water!


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## jockepocke (Nov 24, 2009)

Due to the success of the first setup I continued and improved it. 

I now have a water-boiler (at the A-arrow) in a larger E-flask. This improved efficiency, and also increased the power so much that I added a water-cooling step (at the B-arrow). I get quite much more water now!  Let's hope that it meets the quality requirements!


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## hex1 (Apr 14, 2010)

Try this small inexpensive DeIoniser unit made for aquariums.http://www.amazon.com/Mars-Tap-Wate...ref=sr_1_5?ie=UTF8&s=hi&qid=1271211152&sr=8-5

To check the purity I generally use a Total Disolved Solids meter.http://www.amazon.com/HM-Digital-TD...ref=sr_1_1?ie=UTF8&s=hi&qid=1271211383&sr=1-1 A reading of 0.0 should mean the water is pure. If you do both procedures you should have water that is very close to LAB grade.


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## piotrsko (Dec 9, 2007)

I'm kind of afraid of telling him that distilled water goes for about $2 a gallon here in the USA, and that sometimes it is for sale at the dollar store.

cool process however.


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## Coley (Jul 26, 2007)

It is only $ .90 cents/gal here in our grocery store......

Not worth the trouble....


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## jockepocke (Nov 24, 2009)

Coley said:


> It is only $ .90 cents/gal here in our grocery store......
> 
> Not worth the trouble....


I envy your cheap water, but it is way more expensive here in Sweden (as everything else...). 1 liter goes for about 1,4 $. Anyway, I calculated that with about 30 % efficiency I will get my water at the energy cost of 0,14 $/ L! Plus I consider it fun to build this apparatus! 

I am having some trouble reading the water resistivity... The values seems to fluctuate too much, but I can still se much higher resistivity than of tap water! 

It seems like I will need a platinum elektrode, which I not surprisingly do not have. Tomorrow I will bring a sample to my chemistry teacher as I hope he may have better equipment for the measurements.


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## jockepocke (Nov 24, 2009)

I managed to get hold of a conductivity meter at school! The range is 10 - 1990 (but shows 0 in air) micro siemens (µS), so I could use a more accurate meter...

However, all my measurements gave me the conductivity of 10 µS, which apparently is the lowest value I can measure, but not very pure water. The tap water, for comparison, had a conductivity value of about 180 µS, and I added salt just to check that it worked, and of course conductivity became much higher. 


I found this information somewhere on the web: 

Resistivity (conductivity) of water: 
Ultra -pure: 10-18 MΩ*cm (0,1-0,0555 µS*cm)
Pure: 1-10 (1,0-0,1)
Purified: 1-0,02 (1-50) <--- This is where my water would be placed! 

If all the water batches are max 10 µS, could I use it for my batteries, or do I risk pouring in water that is not pure enough? I would of course measure the conductivity of the deionised water I buy to compare, but I am all out!


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