Why do Batteries go bad?

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Aug 25, 2022
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West Central Indiana
I sold batteries back from 1985 to 1991.
The businessman that I worked for originally sold Deka batteries, made by East Penn Battery MFG. High quality products.
Our salesman would do a great job of educating us about the way batteries are manufactured. Back then a tour of the manufacturing plant wasn't an option.
Larry, the salesman, explained that batteries go bad 4 basic ways:
1. Won't take a charge
2. Won't hold a charge
3. Won't hold a load
4. Physical damage- whether seen or unseen.

Remember too: The electrical power coming from your battery is due to a chemical process. No matter if you have a lead-acid, AGM, Ni-Cd, LI-ion, it's all the result of a chemical process.
Let's look at the oldest and most prevalent; a lead-acid battery. From the moment that the sulphuric acid comes into contact with the lead, the acid is beginning to dissolve (eat away) the lead plates. As this continues throughout the life of the battery the lead plates become thinner and the dissolved lead particles fall to the bottom of the cell. As you can imagine, as this process occurs and heat, vibration, cold all play a part of the lifetime of a battery.
I'm just putting this out there to help you understand.
If your philosophy is buy cheap and keep warrantying- Good for you, it's still America and you have the freedom to do that.
If your philosophy is buy the high quality- Good for you too, It's still America for you.
I am not current on the different battery manufacturers and their manufacturing techniques and so I can't speak to who has the best manufacturing process. It seems that cheap is king in this day and age. Having said that, when I buy a battery, I buy high CCA battery of the largest physical size that will fit the battery box. (I'm a GM guy, so there isn't a huge variation).
 
1-3 are symptoms, not the cause.

The problem is that cost isn't directly related to quality anymore. There is no feasible way for most people to figure out what's good and what's not. This is in general.

Another guy once advised to buy the biggest, lowest CCA battery because they had less plates crammed into the box, which meant the plates were better.

I dunno.
 
1-3 are symptoms, not the cause.

The problem is that cost isn't directly related to quality anymore. There is no feasible way for most people to figure out what's good and what's not. This is in general.

Another guy once advised to buy the biggest, lowest CCA battery because they had less plates crammed into the box, which meant the plates were better.

I dunno.
I'm confused how you can start out saying "1-3 are not the cause". Perhaps you've not had to test a large quantity of batteries...
Then end with "I dunno".
 
I'm confused how you can start out saying "1-3 are not the cause". Perhaps you've not had to test a large quantity of batteries...
Then end with "I dunno".
I think what he's getting at is that it won't take a charge, won't hold a charge, won't hold the charge is the symptom of a larger problem with the battery. Essentially the battery won't hold a charge because XXX failed.

Example, the battery won't hold or take a charge because the 50% of the water evaporated or acid stratification.

Symptom = battery wont take or hold a charge
Cause = acid stratification.
 
I think what he's getting at is that it won't take a charge, won't hold a charge, won't hold the charge is the symptom of a larger problem with the battery. Essentially the battery won't hold a charge because XXX failed.

Example, the battery won't hold or take a charge because the 50% of the water evaporated or acid stratification.

Symptom = battery wont take or hold a charge
Cause = acid stratification.
Can we agree that if any 1 of the 4 are present the battery fails?
Also before properly testing a battery it needs to be full of H2SO4 (ok, distilled H20 may be added because that's what actually evaporates during the power cycle of the battery)
Also, we can get out our specific gravity meter and test the specific gravity of the H2SO4 which will be in proportion to the state of charge.

1. Battery won't take a charge--Before a battery can be tested it must be fully charged. If it won't take a charge=FAIL
2. Battery won't hold a charge--After a fully charged a battery passes a test, said battery is dead the next day=FAIL
3. Battery was fully charged and failed the load test= FAIL
4. Physical damage-- either seen or perhaps the plates inside the battery broke. =FAIL
 
agree

when the inside chemistry goes bad, it will happen what you wrote.
what exactly means, "testing of large quantity of batteries" ?
what kind of instrument? such or better ? https://uk.farnell.com/hioki/bt3554-92/battery-tester-lead-acid-6v-to/dp/3679992?st=hioki battery
Testing large quantities of batteries= testing 1 to 5 batteries/day for 6 years
A good old fashioned, USA built carbon pile battery tester similar, but heavier duty that this; https://cloreautomotive.com/product/1876/
 
Can we agree that if any 1 of the 4 are present the battery fails?
Also before properly testing a battery it needs to be full of H2SO4 (ok, distilled H20 may be added because that's what actually evaporates during the power cycle of the battery)
Also, we can get out our specific gravity meter and test the specific gravity of the H2SO4 which will be in proportion to the state of charge.

1. Battery won't take a charge--Before a battery can be tested it must be fully charged. If it won't take a charge=FAIL
2. Battery won't hold a charge--After a fully charged a battery passes a test, said battery is dead the next day=FAIL
3. Battery was fully charged and failed the load test= FAIL
4. Physical damage-- either seen or perhaps the plates inside the battery broke. =FAIL

We can agree that items 1 through 3 happen because a component inside the battery has failed or degraded and is producing the symptom you are seeing, and could be due to item 4. The symptom you are testing for allows you to determine whether the battery is failing, not the actual cause of why the battery has failed.

I think the problem here is our difference in saying a symptom vs root cause of failure, as the OP basically stated "4 basic ways batteries go bad." Its more accurate to say when a battery is failing, it could produce these symptoms due to XYZ.

Symptom: You test a battery and it won't hold a charge.
Cause: Battery electrodes have degraded
Outcome = Failed battery testing
 
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Batteries used to show signs of aging - weak power to the starter motor when turning over or perhaps not holding a charge after only a short (1week or so) period unused. You had a warning and could plan the replacement, maybe even shop around for a good price.

The last two batteries (two different cars -(GM had a replacement NAPA and a VW with OEM if that matters) failed in a strange manner, started and drove to my destination 1-2 miles away and when I returned to the car turned the key and absolutely nothing -no click, no dashboard lights just nothing. Took the NAPA battery to NAPA and it was dead by their tester. New NAPA battery and all is well for over a year so it wasn’t the alternator or a short. The VW required a trip to the dealer because a computer reset is required after a battery replacement.


What is different with batteries nowadays?
 
Perhaps you've not had to test a large quantity of batteries...
Testing a lot of batteries does not make you a battery expert.
Rather then try to school the folks here, many of whom are pretty knowledgeable about batteries (like this retired electrical engineer) perhaps you should make an effort to school yourself first.

 
The last two batteries (two different cars -(GM had a replacement NAPA and a VW with OEM if that matters) failed in a strange manner, started and drove to my destination 1-2 miles away and when I returned to the car turned the key and absolutely nothing -no click, no dashboard lights just nothing.
All my recent battery failures have been in a similar manner - they worked great until they didn't - however only one went completely dead. I assume one cell shorted and drained the rest. However I am no expert either.

What is different with batteries nowadays?
Value engineering / Six Sigma / Lean - means absolutely zero extra / overdesign / safety factor for anything.
 
i'm not a chemist but as I understand it the H2SO4 reacts with the PbO2 cathode and Pb anode to create a charge difference between the two (voltage). That chemical reaction leaves a coating of PbSO4 on both the anode and cathode that inhibits the reaction (eg weakens the battery). When the battery is recharged most of the SO4 is forced back into solution, but some of the PbSO4 remains on the plates thereby lowering its capacity and eventually killing it with repeated cycling. Some of the SO4 can also fall off and build up at the bottom causing a short.

This is the normal cause of the failure modes described (won't take/hold a charge, etc).

I've never heard of this process referred to as "acid dissolving the plates". I've always thought of it as "sulfation", or the normal process of sulfate buildup inside the battery.

I suppose H2SO4 could in theory dissolve lead plates (again I'm no chemist), but if left uncharged it would just turn to water anyway.

if kept fully charged would the strong acid solution eventually eat away the anode? I have no idea... anyone?
 
In line with the commentary here, this morning I went to start my Jeep and nothing - no lights, no shut-your-door-stupid alarm dinging, zilch. Got out the NOCO boost, connected it to the battery ( a 2 year old NAPA ) and after a few minutes of letting it percolate, it started right up. Then after a warm up I connected the diagnostic meter to the OBD, and went through the list. The alternator is putting out 13.8, the battery registered good at 13.7, disconnected everything and did a restart - no problem.

So is this an indicator of something, and if so, what ??? I've encountered this before and batteries have had a 'glitch' and then run on for years.

Thanks in advance.
 
Outside opinion: of the 30ish vehicles I've owned, I think I've had to replace the battery in MAYBE 3 of them. The factory AGM battery in my 2013 Volt kicked the bucket the 2nd winter I stored it, I put a battery in my '96 Aurora back in the day, and there was maybe one other I'm forgetting. I live in MN, not someplace known to be "easy" on batteries.

I'm a firm believer that the best way to maintain a battery is to DRIVE the thing. For the last 20 years, my daily commute consisted of at least 10-20 miles one way. Maybe not ideal, but the fact that every one of my vehicles started even in -25 degree mornings says a lot.
 
Another guy once advised to buy the biggest, lowest CCA battery because they had less plates crammed into the box, which meant the plates were better.

I dunno.
Two batteries, of the same size, but with different CCA ratings...the lower rated one will have fewer plates, usually further apart (separated). Most batteries will die from sulfation. This is from the plates shorting out...if the plates are further apart, they can be more resistant to shorting from sulfation. So yes, high CCA batteries can often have shorter life as the manufacturer packs more plates in the same size box.
 
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