Results of testing old batteries which have been desulphated

[mael]

I wish I could edit sometimes.

a possible film of canon-conductive calcium off the plates

...non-conducting...

[Amr]

Smart liquid and army of tiny welders is the optimum solution for all our problems I wounder when they will exist!!!

Meal, from what you described for the behavior of your battery and from what I noticed on similar batteries , if a battery can keep a V reading for above 12.6 but quickly drops when loaded, this is an internal short or high internal resistance, if the internal resistance is at the internal connections, this in my opinion will not make you feel the battery is getting hot while you are charging it or while you are discharging it because the internal connections part that will cause the problem (the pivot) should be above the electrolyte level, you may feel the warmth with an infrared temperature sensor directed at the top of these connections but the battery will not heat up.

In the case of your battery, and as long as you did not find much impurities in the electrolyte when you drained it, then I would eliminate the possibility of consumed plates, when the plates are consumed, particles of the lead will settle down in the battery and the electrolyte will be dark in color, when you filter it, dark impurities (lead) will show in your filler.

I have no experience with calcium based batteries so I cant help in this area, but my understanding is that if it is mechanically sound, then why not treat it the same way as desulfating normal batteries? may be a higher or lower current is needed but the concept should be the same.

Traction/ deep cycle batteries has thicker plates as you know, so chances and time needed to consume (cause a hole) in the plates takes more sever circumstances and time, that is why their repair rate should be higher than other batteries.

Tetrasodium / EDITA did not work with me, I'm contacting some people who claim they have better chemicals that removes sulfate, I hope they are not cheaters, if I buy any of them and they turn out to be true, I will tell you.

You say your pulsars are dangerous to the uninitiated, isnt that the case with all our desulfators? the difference will be that your's give assured results.

[mael]

Actually I had a thought a couple of days ago about that disappointing battery.

I reckon that battery's problem is the connections from the plates to the connectors above & between the cells.

I'm buggered if I want to do an autopsy because invariably I get acid everywhere and it's a messy job. But just to put this mystery to rest I ought to cut away the casing to expose the plate's connections to the bar above.

I've seen this before on another battery. I just decided I wanted to use the case for something, and whilst removing the innards I noticed over half the plate's connections at the top had gone, and that what connections remained were quite delicate.

That battery also showed it wasn't shorted.

If this is the case then it's too much trouble to fix, so the battery is toast.

*

... And the way you're going to find a battery with plate connections which have eroded or gone is the cranking-test. - Maybe there are ten plates in a cell. Maybe some cells only have on or two viable connected plates left. So the result is going to be what those one or two plates is capable of delivering. - "The Weakest link in the chain" - so to speak.

[mael]

[mael]

Well!

AUTOPSY OF LARGE M/CYCLE BATTERY

First I emptied the acid.

I cut open the case. I did it with a 'box-cutter.' I held a very small butane torch in my left hand and trained the flame on the blade which was in my right.

I cut open all around the top of the battery in a band. The band was from the top part of the battery case to the top of the plate assemblies.

I wanted to see if the 'combs' which the plates attach to were broken. On a superficial examination it seemed all the plates were attached to at least the top of the plates.

I cut one of the end cell's plastic casing off so I could expose all the plates in that cell. I noticed that all the negative plates were well-fixed. But this wasn't surprising as they are made of solid lead. - but the positive plates were rotten.

The positive plates are lead 'paste' on a lead lattice/grid. Every positive plate was attached to the above 'comb' by the top horizontal piece of the grid. But the lines of lead which lead down into the plates from there were mostly disconnected.

.

By prying off the solid neg plates I exposed the positive plates. Without exception the positive plates were just lead-powder sandwiched between the negative plates, and were only held in place because they were pressed in by the insulators and the neg plates.

For example:- The top of the grid of the pos plate has five pieces leading downwards - in a good battery. But with these only two might have been connected.

So the reason this battery failed was the degradation and degeneration of the positive grids.

With this battery, only a portion of the grid was intact. So basically the battery lost cranking power and capacity because it was effectively a smaller battery by virtue of the fact that the active plates were smaller.

* This battery had some crud in the top. Perhaps some of it could have shorted some plates in some cells. This crud seemed to come from the connecting inter-cell bars. It was flakey.

* The electrolyte was fairly cloudy. This might be a clear indication of the positive plates turning to mush.

* The plate assemblies were a tight fit. Not unduly distended. I couldn't see much chance for any crud on the top of the plates being able to find their way to the well at the bottom.

Interesting! I want to find a reliable way of testing the integrity of the positive grid ... Oh! I know! A cranking test!

I can't see a way to fix such a problem. - Clearly a battery made with solid plates will last longer than a starter battery! They're CRAP!

[sciencisto]

Exactly as you said, that kind of batteries are crap. I dismantled many of them. It looks like they were build to withstand no more than just a few years.
So, the conclusion is simple, if you want reliable battery that can work for hundreds of years, just build one yourself. It is easy and simple.

And remember one basic thing -- lead acid batteries are to be charged with PULSED current only, NEVER ever with direct current or they will be destroyed soon.

[Amr]

J hate it when I miss or dont receive a reply notification!!!!

Any how, interesting observations Meal. and yes, cranking test for starting batteries is an important indicator. But cranking test for traction batteries is not practical, traction batteries should provide deep discharge (till 10.5 V) but can not deliver high power for starting an engine unless you over rate it, over rating is more money, weight and size.

Sciencisto, maybe building your own battery is fine, but I think it may cost more than buying a new one, after all, ready made ones are mass production and should cost less.

You said that charging lead acid batteries should be only with a pulsed charger, I dont know about that, car charging alternator is not pulsed, yet, with proper usage, good batteries may last for long worth their price. I agree that pulsed charging is good for batteries every now and then, but as soon as you get rid of sulfate, what good would it be for the battery?

[sciencisto]

[mael]

[mael]

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[Amr]

[mael]

[Amr]

[Amr]