Results of testing old batteries which have been desulphated

[Amr]

[mael]

Hello AMR

[quote]The only thing in the world that defies the known laws is the Pyramid ï

[Amr]

Now, this either is a step forward or an illusion!! That is why any input from someone who understand chemistry will be very helpful, chemistry was my most hated subject back at school times (30+ years ago)

I've been thinking about shorted cells. And I'm talking here about shorts resulting from sulfation and not peaces of metals falling apart inside the battery. As we all know, this short is a result growing crystals of Lead(II) sulfate, they grow to the extent that they pass the separator between the – and + plates and cause a short. Pulsing will not remove this short neither it will correct it obviously as in this case, the two plates will behave as a one connector and hence, - and + polarities needed for the pulse to work does not exist.

But what about if we could chemically remove lead sulfate crystals? They are a layer of a material (a component made from lead and sulfate) that is covering lead. Many plumping works at homes were originally from pure lead especially the junction from sinks to drain systems, a product is used to clear any blocking in them that eats away any thing but lead and plastics, this product is sodium hydroxide.

So, I did a little test, that battery I was speaking of in my last post, 5 good cells that their electrolyte is measuring more than green and one cell that does not register even in red, I left it on a slaw 2 Amps charger for about a weak till last night, battery warm and V does not get any better than 12.31 V while under charge with that slow charger. I put some sink cleaner and left for an hour, V kept on rising and it is now (24 hours later) 13.01 !!!! I will leave it hoping it will go to high 14th and then remove the charger and see what will happen.

The good thing here is that the electrolyte is now in the mid red, so there defiantly is an improvement, even if it did not totally recover this way, still, another attempt by pulsing may then work.

I don’t think that sodium hydroxide is what made the electrolyte show better reading on the battery tester, I wanted to make sure of that, I took some water (it must be boiling water for the sink cleaner to work) and I put some cleaner in it, the tester stayed over the red, I took another totally dead battery with 9 shorted cells out of 6 and I drained its electrolyte and replaced it with boiled water and sink cleaner, few moments later, no charger attached, the electrolyte is in mid red. so it looks like lead sulfate is being diluted in the sink cleaner. This battery's total open V is currently 2.14 !!!! I will repeat this treatment another time and then hook up a charger or pulser and see what will happen.

I don’t yet know the effect of this test on the paste covering the plates nor on the separators, but I think in some time we may find out.

I also do not think this might work on gell cell batteries as it is highly expected to affect the gell material.

But what I do certainly know is that this is a very dangerous test and safety procedures must be taken before doing it, if you want to try it, try it at your own responsibility.

PS: this material does not react with cold water.

And Mael, tomorrow I will start looking for that bench top welder, wish me luck.

[mael]

I'm not so good at chemistry, but I wanted to comment on what you said about the sulphates.

As far as I know, lead sulphate is non-conductive, and the reason for the shorts is due to the sulphate crystals growing and pushing the plates together.

The plates which are bent will crack and with the vibration from an engine they will fall to bits rapidly - especially the compact high-calcium ones.

So I think that simply chemically removing the sulphates will by no means make the battery servicable again.

NaOH is an alkali, and the battery electrolyte is acid. I wonder what that will do to a battery? I have heard of people using baking soda (alkali) in a water solution and some people say those batteries are as good as they were when they had sulphuric acid in them - I tried it once and it wasn't very successful. It worked, but only went through a few cycles before it took ages to charge and minutes to discharge.

But - having said that, you might be onto something. I hope someone with knowledge of chemistry can set us straight.

[Amr]

When I got the idea, i was very eager to try it and to present to every one something that looks a simple solution to a big problem. I did add the cleaner to the cell that is beside the – pole which was already in good condition and not the one beside the + pole of the battery.

I will start all over again and tell you what will happen.

Mael: You made a valid point, I will take it into consideration, there may be plates cracked due to sever sulfation of course, but I thought that this is when the exterior of the battery will lock deformed only.
I will try using the sink cleaner as a bath for the interior of the battery and then replace with new water and see.

Sorry everyone if I gave a false hope.

[Jehu]

just a little tip for you guys. I've only read the last few posts but that doesn't really matter in this context.

If you add an alkali (base) like NaOH to an acid what will happen? The acid will be netralised. It should by rights form Sodium Sulfate. Now what effect this has on battery operation, I don't know, not my field.

About the Baking Soda. Baking soda is a base, however, in some cases it can also act like an acid. I'm not sure what this would make when you add it to the H2SO4 let alone any reactions with the plate metal/s.

Hope this helps.

[Amr]

[Amr]

[SeaMonkey]

It is good to see continued interest in lead acid
battery rejuvenation - the ongoing exchange of
ideas between Amr and Mael is both interesting
and beneficial for all who 'tune in' to this thread.

We'll be 'watching' and learning as you continue
your experimentation...

[Amr]

Thank you SeaMonkey, but I must give all the credit to Mael, you, and ‎every one who gave an input in this thread, you are way ahead of me ‎and I learned a lot from you.‎

The 60A battery I mentioned above did not improve by the automatic ‎charger, after the green light of fully charged indicator on the charger ‎was on, I removed the cables and down it went, the V kept on falling ‎very fast, so I have it now on the continuace 2 Amps charging position, I want to ‎give it a chance to prove which method is better in rejuvenation ‎batteries: if a long topping charge did not work, then I will be pulsing it, ‎this will prove which way is better to do it although I'm almost certain ‎that pulsing is quicker and will give better results. Is it possible that it ‎has an internal short? it was not miss-used by my friend (no lights ‎forgotten in the on position for a long time) and the production date is only 6 months ‎earlier, nothing loose inside to indicate broken plates, more over, both ‎the car and the battery are German made so there is a very slim chance ‎it has a manufacturing problem. I think it was left for a long time in a no ‎use condition, probably for several months with no recharging after the ‎battery was produced by the factory.‎

It is time to get a digital battery analyzer, I found one here ‎http://www.boridenergy.com/Battery_Analyzer.html but was wondering if ‎any one know of or is using a digital analyzer that is giving reliable ‎results and not as expansive as this one.‎

[SeaMonkey]

For those who may be wondering what kind of
circuit Mael has been developing and how it
looks 'schematically'
will provide information on a closely similar sort
of circuit. Discussion and diagrams are presented.

It is possible to modify the circuit for use
with conventional transistors instead of MOS Fets
and to use other chips than the 555 for the
pulsing portion of the circuit.

The advantage of the pulsed DC circuit over the
'normal' inductive discharge desulfator circuit is
that the 'pulses' of pulsed DC can be much more
powerful and of longer duration. This enables
efficient desulfation as well as efficient charging
of the battery being rejuvenated - particularly if
it is a large battery.

Additionally, the pulse width can be very easily adjusted
to produce extremely short pulses for desulfation only,
medium length pulses for desulfation and charging,
or longer pulses for principally charging a battery.

[Amr]

[Amr]

[SeaMonkey]

[mael]