Reversed cell?

[zap]

Late in winter I found an Interstate SRM-24 (deep cycle/starting) sitting next to the city's recycle bins.  The bins are meant for glass, papper, plastic, etc. only and since batteries are a no-no, and since I'm such a model citizen, I came back with a meter to check it and possibly remove it from the city's property.  It showed around 5v but looked almost brand new.

I brought it back home and hooked it to a charger and it wouldn't even take 1 amp.  I did a discharge which didn't last long till it was down to around 3v and hooked it back up to the charger which now managed to push about 6 amp into it.  I did the charge/discharge routine a few times till the battery was holding a good charge and then hooked it up to the solar string of batteries hoping the Morningstar's PWM would help the battery out.

Skip ahead a few months and my trucks starting battery was showing signs of death.  At 10 years old, I felt I had received more than my money's worth.  By now the Interstate wasn't perfect but was looking like a good candidate to replace the truck's 10 year old DieHard Silver.  I swapped the DieHard with the Interstate and got a few months starts out of it till this week.  With the price of gas, my bike has been my main transportation so the truck has sat, at times, for weeks without any use.  It was reading 10.6v, a good indication of one bad cell.

I hooked the charger to the truck and the Interstate took a charge but I noticed one cell wasn't showing much action.  I did a discharge on it and the inactive cell immediately commenced to bubbling.  I took this as a sign that the cell may have reversed.  Is the assumption correct?

Following that fairly deep discharge the battery's bad cell did show some sign of life but the battery would drop to 10.6v again after sitting so I did a deep discharge down to around 2v.  The bad cell was bubbling like crazy the whole time then I hooked it back up to the charger to charge at 2 amp over night but still no go.  The cell's specific gravity shows dead even after it has been bubbling after a long discharge.

Anyone have any "home remedies" for a reversed cell, if indeed the cell is reversed.

The only thing I could find, both here and on google was someone saying "put a resistor on the battery overnight".  : (

Thanks

[dnix71]

You might save it with a desulfator. The cell that perks like that probably has mechanical damage by now, but new batteries are $75, so if you have a desulfator, you have little to lose.

Vector battery chargers have a desulfate function.

http://www.amazon.com/Vector-VEC1088A-Smart-Battery-Charger/dp/B00009RB0R

Some of the customers used this model to resurrect dying batteries.

It was sold at Walmart.

I used a similar model to repair an sla that my boss had in a Vector portable air pump/car jump starter/battery charger.

[dnix71]

Google this term without the quotes. There are plenty of places that have it. I don't know why Amazon claims it's not available.

"Vector VEC1088A"

[zap]

Thanks dnix71.  I've had a Black & Decker VEC1089ABD for a few years and the Interstate was on it's desulfator mode for about a month and a half after I first found the battery and after I started getting it to take a charge.  I noticed no difference in the battery after that month and a half.

I also had it on a 555 based desulfator and later let it run for a few days on the watergas desulfator and didn't see any result from either of those.

I'll keep messing with it till it gets well, blows up, or I just get tired of messing with it.

[Flux]

Zap

You seem to have had as much luck reclaiming dead batteries as I have. I gave up trying years ago. nothing I ever tried gave reliable results good enough to risk using the things.

Desuplhators don't desulphate as far as I can see. They sometimes do something to improve poor contact between the active material and the grids but not long term reliably.

In the old days when it was possible to remove one cell I usually found the cause of an open circuit cell to be a corroded positive grid bar and nothing will correct that.

Shorted cells were usually warped and shorted plates or from crystal growth through the separators, sometimes a short could be removed for a while. Modern batteries don't lend themselves to dismantling and probably just as well, it was a dirty time consuming job with little success rate and looking back at it it seems dangerous.

Flux

[Norm]

Yes it was a dirty dangerous job...remember back

then a guy that rebuilt batteries....his work

clothes were full of holes despite rubber aprons

and such....

and his rebuilt batteries didn't last very long either

because sooner or later another weak cell in the

series would give out

[zap]

Flux,

Thank you for the comments.

I would say I'm pretty much in-step with you and your feelings on desulfation as I've read many of your comments on it over the years.  And for me, so far, a deep discharge(s) followed by a healthy recharge(s) has brought more positive results than anything else.

The only thing keeping me from sharing what I assume to be your exact feelings on the subject are the many "successes" I've read from others using the 555 circuits, water gas circuits, electric fence apparatus, EDTA, etc.  Maybe it's the fact that every sick battery I've come across wasn't suffering from sulfation... or it was a combination of sulfation along with other symptoms.  I don't know.  And I have never been able to bring myself to purposely sulfate a good battery just to test.

Batteries and battery rejuvenation has always seemed like a bit of a 'black art' to me  and I've never seemed to quite 'get it' and seeing different behavior from almost every battery just distances me further from understanding it.

Such is the case with this Interstate battery.  Why would the one cell in question boil like crazy, as if it's being charged, when the battery is being discharged but even after an almost total discharge, that cell's SG still shows dead?  I would think (obviously wrongly) that the cell in question would show an SG of full or at least a rise, even though it has reverse polarity.  I would also think that if the cell was shorted then even with a few 10's of amps flowing through it when the battery is being discharged, said cell wouldn't be showing the bubbling this cell does since most of the current would just be shunted through it.  This cell bubbles as if it's using most of the plate surface.

I'm only 'out' my time on this battery and a few Kwh running the charger so I guess I'll keep at it for now.

[Flux]

I will only comment briefly, as you say there are many about that are convinced by this desulphating idea. If they get good results there is no reason for me to question it.

Like you I also thought I must have batteries with other faults than sulphate, there is very little way of knowing what is wrong without seeing inside. I did eventually find one that I am sure was suffering from nothing other than severe suphation and the pulse charger things did absolutely nothing to it. They may be of some use at catching it in the very early stages ( most likely at this point a good equalising would also work).

The whole basis of this concept seems to be battery resonance and that turns out to be a function of the inductance of the length of conductor ( one end of the battery to the other). This combined with quite stupid assumed pulse currents again due to measurement error ( I think they have accepted that one ) gives me little faith. They also go on to say that there will be no rise in sg from this process so how does that add up.

What I think has happened to your battery is that the positive grid bars are corroded. Circuit is still possible via partial contact and through the electrolyte so that cell still charges and discharges. On application of a heavy current there is a volt drop across the poor area with sufficient volts to cause electrolysis ( boiling) that you see.

If the failure is between grids and the paste then pulsing may do some good ( at least temporarily). If the main link bar is corroded then there is no hope.

Flux

[zap]

"What I think has happened..."

Going by this and with your experience I'd say it's a lost cause.  I'll give the desulfator another shot and see since I don't have much to lose.