Lots of battery discussions of late. I’ll add mine. Except for batteries that go stone cold dead, I don’t think any two have ever failed the same way.
So I have this flooded wet cell unit, old school, in my 65 AC car and have been experiencing this. Battery sits on a “high tech” maintainer. This summer I went through the drill and pulled the unit to check it. Acid level had fallen to the top of the plates, maybe slightly exposed on a few. Filled with distilled water, cleaned everything including connections and reinstalled and recharged. Next use, started right up, no apparent issues. A bit later I start and back out of the garage and it sits the day while I do other things. Tried to start to pull into the garage, no crank, grunt, then click. Roll start and return to garage and replaced on maintainer. Not long till fully charged. This happens again, maybe 3-4 times. Desulphate the battery, no change.
Today, started right up after removing from the maintainer, backed onto drive and sat for several hours. Go to start it to return to the garage and would not roll start. Connected jumpers to another, same grunt, then click. Started the boost vehicle and it cranked and started. Pull into garage.
Voltage was 12.8 ish. Car cranked 2 times and started, grunted the 3rd. Battery voltage 12.68. Turned on headlights and voltage drops to 9.66 over a couple of minutes and holds for several minutes. Turn off headlights and battery recovers steadily to 12.68v over a minute. Cycled this again with exact same results.
Experience tells me there is not a dead cell, but it fails under load. Surprises me that under load voltage drop stops at 9.66/9.68 and then fairly quickly recovers without charging.
With the difficulty of access, it’s coming out and replaced, but this data seems quite strange and not typical for failure in my experience.
Thoughts?

PS: Not sure of age, but more than 2 in my possession.

 

Pop:
Same failure mode happened to me with a group 29 wet cell commercial line battery from NAPA made by Exide. Exactly the same as you describe. I have also experienced case leaks with these and have ranted as much on a separate thread. Why is it happening exactly I cannot say, internal short, impurities in the liquid, deliberate production of a piece of garbage, not sure exactly.

Dan

 

There is usually a Julian date code cast into the side or top of the battery. You can have it load-tested but IMHO, while I expect to get 5 years out of a battery, one that is 2+ years old and doing funky stuff is getting replaced. Some of the older maintainers tend to cook the battery over time... the fact that you were that low on acid would make me suspect that. I think the newer smart maintainers do a better job of monitoring the battery and only coming on when the voltage drops.

 

Yes, I've quite using maintainers except on a boat marine battery - I just don't trust them. I use a cutoff and I typically have good luck with batteries, 18 - 13 years on my old cars I would estimate. Sometimes, if one seems to be getting a little weak I will find a cell or two that are low on electrolyte and top them off and usually get another year or two out of it

 

The same always check the bar code for build date and if on battery date record that. Then mark on battery date you installed. I bought a five year battery and it died right on three years. Come to find out date on battery said it was two years old at the time i purchased it, so i did get five years. At the same time my napa died right on three years and left me stranded.so now i go no were with out my portable high tech quick starter. The only battery that gave me any security was the AC Delco i installed in my Corvette. As far as battery tenders some i have found are junk and others you have to watch very closely.

 

Pop, you say you desulfated the battery. What procedure do you use to do that?

What maintainer are you using?

GUSTO

 

Maintainers are overrated IMHO and even the best ones will shorten overall battery life even if they don't cook the battery in just a few years. Correct parasitic draw and disconnect when not driving, and give a top charge after long periods of disuse . My NAPA batteries (made by East Penn) have lasted 10 + years operating this way. Just bought another today and got a full refund for that POS Excide minus my cleanup trouble.

 

This one: (Recond means desulfate)

 

Any auto parts house or battery store can load test the battery. To over simplify, you have good voltage but not much of it.

 

Never tried it myself, but I heard a good tip to avoid cooking a battery when using a cheap / old maintainer is to put it on a household timer that plugs into an outlet so it only runs a few hours every few days.

 

I wish I'd had as much luck as Fake with AD Delco batteries. I'm on my 3rd AC Delco battery in my '67 A/C coupe right now. The first one failed after 46 months and was generously replaced on warranty (even though the guarantee was for 42 months) The replacement flunked after 4 months so back out it went. Again my parts place graciously replaced it at no cost, so credit to them for that.

The only bummer is mine is a factory A/C car so replacing the battery is a 2 hour job - the front left wheel needs to come off to get the battery out through the wheelwell hatch. Someone on this Forum later told me there's just enough room to get the battery out by turning the wheels all the way to the left. That saves removing the wheel. I'm gonna try that next time!

The only battery brand I've had good luck with is Die Hard, which I have in my other cars. Maybe I just got lucky with those. It seems most any brand of battery can flunk unexpectedly these days.

 

Pop, the CTEK is an excellent 'maintainer' and should be capable of removing sulfate deposits off of the lead plates under most circumstances.

A couple of things to keep in mind regarding battery sulfation are first, depending on the size of the battery, the desulfation process can take from 48 hours to weeks, to complete. During this period the battery will need to be trickle charged (maintained) to continue reducing the amount of lead sulfur in solution. Second, If the sulfation is too advanced, then you may not be able to remove it from the lead plates. If it has only just started to occur, you can typically remove it by gently recharging the cells.

What is sulfation? During use, small sulfate crystals form, but these are normal and are not harmful. During prolonged charge deprivation, however, the amorphous lead sulfate converts to a stable crystalline and deposits on the negative plates. This leads to the development of large crystals that reduce the battery’s active material, which is responsible for the performance.

There are two types of sulfation: reversible (or soft sulfation), and permanent (or hard sulfation). If a battery is serviced early, reversible sulfation can often be corrected by applying an overcharge to an already fully charged battery in the form of a regulated current of about 200mA. The battery terminal voltage is allowed to rise to between 2.50 and 2.66V/cell (15 and 16V on a 12V mono block) for about 24 hours. Increasing the battery temperature to 50–60°C (122–140°F) during the corrective service further helps in dissolving the crystals.

Permanent sulfation sets in when the battery has been in a low state-of-charge for weeks or months. At this stage, no form of restoration seems possible; however, the recovery yield is not fully understood. To everyone’s amazement, new lead acid batteries can often be fully restored after dwelling in a low-voltage condition for many weeks. Other factors may play a role.

A subtle indication whether lead acid can be recovered or not is visible on the voltage discharge curve. If a fully charged battery retains a stable voltage profile on discharge, chances of reactivation are better than if the voltage drops rapidly with load.

Several companies offer anti-sulfation devices that apply pulses to the battery terminals to prevent and reverse sulfation. Such technologies will lower the sulfation on a healthy battery, but they cannot effectively reverse the condition once present. It’s a “one size fits all” approach and the method is unscientific.

Applying random pulses or blindly inducing an overcharge can harm the battery by promoting grid corrosion. There are no simple methods to measure sulfation, nor are commercial chargers available that apply a calculated overcharge to dissolve the crystals. As with medicine, the most effective remedy is to apply a corrective service for the time needed and not longer.

While anti-sulfation devices can reverse the condition, some battery manufacturers do not recommend the treatment as it tends to create soft shorts that may increase self-discharge. Furthermore, the pulses contain ripple voltage that causes some heating of the battery. Battery manufacturers specify the allowable ripple when charging lead acid batteries. See; https://batteryuniversity.com/learn/..._to_prevent_it

There are also quite a few videos on the internet, some from very reputable sources that cover their method for desulfating a battery. Here is one from NOCO, the manufacturer of Genius Chargers you may find interesting.

How to Desulfate a Lead Acid Battery" target="_blank">How to Desulfate a Lead Acid Battery

Good luck... GUSTO