Dead Cells

[ckoretsky]

5 rolls surrette batteries 12-HHG-8D 1,000.00 each. 10 years old. But only used for 4 years. In each battery, 5 of the 6 cells have perfect specific gravity readings, and one cell that doesn't even move the needle. So they are worthless. That doesn't make any sense to me. There has to be a way to take out the bad cells. and replace them. Aren't they supposed to be like 6 seperate batteries in series? And what about the desulfation? Has anyone ever had that work?

And what's going on inside the batteries to make only one cell go bad?

[NotQuiteLost]

What very little I know of batteries is that this is how batteries fail. One cell gets progressively worse until it literally kills the connectivity between the others, and the voltage dies as a result.

I know shops locally in the Philippines that do, in fact, perform battery 'repair,' and they do essentially what you're suggesting. they shave lead off the bottom of the batteries to make them uniform/healthy there so that the accumulating flakes won't kill the batteries too quickly, and they re-fill the electrolyte. You have maybe 10-20% less lead, but the guys I've talked to say it seems to work about as well as you could hope.

Had never heard of people doing this before coming here, but my battery knowledge has been recently acquired.

[ckoretsky]

That's not even a word. i've about given up on these batteries, one last ditch effort. I emptied out all the acid from the dead cells in two batteries. One dead cell had reddish grey water, the other was clear. I put fresh sulfuric acid in both and hooked them up. I have the engine running now, all the cells are bubbling a little, except for the dead ones. the alternator is putting out 17 amps, 10 of them are going into the one with the grey/red water. 5 into the other one.

I'm just trying to get things going. Then I will empty out the acid, and put distilled water back in.

[AnchorageGuy]

You might try DC Battery Systems at 305-758-5041 or East Coast Battery Distributors at 954-522-2403. They are Rolls distributors. You don't say where you are located. Chuck

[Bash]

I don't think I've ever had a battery fail that wasn't because of a single bad cell. That's the system.

Trying to revive 10-year old batteries, especially batteries that have apparently been neglected, seems to be an exercise in futility.

[btrayfors]

Yeah, and mighty dangerous, too.

I'd toss those batteries fast; don't try any heroics. If you were in the Phillipines or other LDC where folks are incredibly bold and experienced at reviving old carcasses, that would be something else. Otherwise, forget it.

Sounds like those batteries have been badly neglected and are likely heavily sulfated (that is a word, BTW), i.e., lead sulfate (PbSO4) crystals have built up and become permanently embedded in the plates. You can't rid the batteries of these capacity-killers. Could be lots of other things in addition to the sulfation....stratification, bent plates, buildup of sloughed off material under the plates, shorting them out; contamination; etc.. And now, you've screwed with the electrolyte and are unlikely to ever get it right.

Cut your losses and get new batteries and take care of them. Depending on what you're doing on the boat, you may get by with much less expensive batteries and much less capacity for the time being.

Bill

[NotQuiteLost]

If you know the specific gravity of the other cells is close/right, you can just get one of the old-fashioned bulb testers and keep diluting the acid until the gravity is right for the electrolyte mix. But it really is dangerous.

But then, it really is a long-shot and can be quite dangerous to overcharge batteries. When you're equalizing (pouring a massive voltage into the batteries to remove surface sulfation) make absolutely sure that you've got the batteries well ventilated, as the gas buildup is quite noticeable even with a bit of a breeze blowing through.

At this point, I'd ask a professional to take a look. I'm sure they can work with you on them, or at least give you them their last rites so you can move on with a bit of dignity. It does suck when batteries go out.

[ckoretsky]

'so.k. I like danger. I've been trying to pour a massive voltage into the batteries to remove surface sulfation but I believe I have to "full field" the alternator in order to do that. So far I haven't been able to get it right. Turns out the Balmer wasn't even putting out, and I think the Hitachi might be grounded inside, is that why it didn't full field when I jumped from hot to field? Supposed to go from ground to field? I'm looking for the amps to go up not down, I think. Then they will start to churn and boil and and break off all the lead sulfite which is filling all the holes. so the +'s can't get through. Then I will remove the H2S04 catalyst and put the old electrolyte back in and hope I haven't screwed with the electrolyte so that it will never be right again.

The batteries are outside so no fumes, I get a big whiff of chlorine gas every once in awhile, when I forget not to rinse things with salt water. Takes my breath away.

and I doubt I could persuade an electrician get in my row boat.

[ckoretsky]

One more dumb question: I don't know if all batteries are this way, but mine have little holes where you can check the voltage of each cell. So why can't I charge just the dead cell?