'14 Audi A6 TDI - OEM Battery - EOL?

[SaVAGeSoot]

As some of you may recall, I've previously posted evidence of the battery that I "found" in the truck of a vehicle I acquired earlier this year.
I was shocked that it is still the original battery. I have been periodically keeping at eye on it, and now that winter is upon us, I'm starting to sweat a little due to my procrastination in replacing it.
Worth mentioning is that I also recently picked up a cheap Chinesium battery tester off Amazon, because.... I can. I really just wanted another toy, and my excuse for needing it was that I can quickly check the condition of the batteries on our family's 4 vehicles, as well as any friends\neighbours that I want to give a quick hand to. Pretty much everyone experiences failed batteries at some point.

Anyways, I'm making this post, to document my findings and to provide some entertainment for those of you that follow along until I manage to get myself stranded, or whatever.

Here's what we've seen thus far.

First look at history file shortly after buying the vehicle.

Visual confirmation of what the history file was telling me, a few days later.

Another check months later, after noticing a slow crank

... more to come....

 

[SaVAGeSoot]

And here's what the battery testing is reporting now, after the vehicle has been parked a few days out in the elements post last use.

 

[Uwe]

Another check months later, after noticing a slow crank

I'm sure you're aware that a slow crank can have causes other than the battery.

And here's what the battery testing is reporting now,

How does a crappy little tester like that measure the capacity of a battery?

What happens if you disconnect the negative cable of the battery, charge it fully, and and then let it rest for 12-24h?

-Uwe-

 

[davisev5225]

How does a crappy little tester like that measure the capacity of a battery?

Microprocessor with extremely accurate voltage measurements... though I've never heard of the "Motopower" brand, so I have no idea how accurate it actually is. I have a similar unit made by Autel (so at least reputable), but I only use it to determine if it's worth the effort to pull a battery and go to my local auto parts store for a proper load tester to get applied.

 

[Uwe]

I have a similar unit made by Autel (so at least reputable),

Uhm... Yeah. Sure.

I only use it to determine if it's worth the effort to pull a battery and go to my local auto parts store for a proper load tester to get applied.

Yup. That's the proper way to test a battery. There's simply no way a little box like that can load-test one; the energy dissipated would smoke it.

-Uwe-

 

[davisev5225]

Uhm... Yeah. Sure.

The number of professional shops that use Autel diagnostic tools renders your sarcasm moot.

 

[evisceratum]

I believe that an internal resistance of 5.8mOhm states a dying battery. A new battery is arround 2mOhm. Obviously it will work and charge but the voltage drop at cranking will be significant. For example a VW car modules will not like it at all.

 

[SaVAGeSoot]

Everyone calm down! (I can't believe, that I'M THE ONE actually saying that)
I'm not claiming this battery is fine! I have full intent to replace it, as I've shown from the very beginning of posting any details about it.
I'm simply sharing some info\findings, not to try to convince anyone that the battery is good, or that my Amazon brand tester is the best, or anything like that... just sharing info to be used if anyone wants to, however they see fit.
We just got a bunch of snow dumped on us, but I'll see if I can get a chance to do some more tests with the cheapie tester... it appears to have some sort of starting voltage chart measurement feature or something too.... I fully expect that we will see a large voltage drop from this battery, etc.

Here's another reading I took off it after throwing a charge onto it for about 12hrs or so.... as you can see, not a whole lot of charge went into it, so that's another tell tale sign that it's pooched.

 

[SaVAGeSoot]

Something that I found really interesting, is what I saw when I decided to throw this tester onto my old Touareg's battery, that I replaced 2.5 years ago.
This battery has been sitting on my bench in the garage, and I've had a trickle charger onto it randomly, but for significant periods of time. The intent was to have a 12v source if I wanted to quickly use something stupid like a small road side air compressor or a inflator pump (for floaty toys) or any other "hook up to a car battery type" thingy... (which I've never needed - fail)

However, when I threw the tester onto it, I was shocked at the report.

From these original stats

Saturday,09,April,2022,10:39:15:38535

  IDE00019   Voltage terminal 30 11.5 V
  IDE01833-MAS03159   Battery version-Manufacturer Varta
  IDE01833-MAS04490   Battery version-Size 110 Ah
  IDE01839   Battery charge level 54 %
  IDE01840   Battery condition for display 50 %
  IDE01842   Usable battery charge 15 Ah

So now I'm wondering.... is it actually possibly that this Amazon "smart trickle charger" (I'd laugh if it's another "Motopower brand") could've actually restored some life in this battery by slowly charging\reconditioning it over an extended period of time? I'll have to put some loads on it to see if it can actually do "something", but I'm quite curious now.

 

[davisev5225]

So now I'm wondering.... is it actually possibly that this Amazon "smart trickle charger" (I'd laugh if it's another "Motopower brand") could've actually restored some life in this battery by slowly charging\reconditioning it over an extended period of time? I'll have to put some loads on it to see if it can actually do "something", but I'm quite curious now.

It's possible if it uses pulsed power to trickle charge instead of constant current, though usually such a "reconditioned" state doesn't stick around in the long-term. Once a lead-acid battery starts to sulfate, there's really no going back without at least changing the acid if you're lucky, and the plates if you're not (which might as well mean "replace the battery" at that point).

 

[SaVAGeSoot]

It's possible if it uses pulsed power to trickle charge instead of constant current, though usually such a "reconditioned" state doesn't stick around in the long-term. Once a lead-acid battery starts to sulfate, there's really no going back without at least changing the acid if you're lucky, and the plates if you're not (which might as well mean "replace the battery" at that point).

Yeah, to be honest, I'm not expecting a miracle, but it could potentially mean that I could further procrastinate replacing the A6 battery until spring perhaps.... since the A6 is mostly a driveway ornament, I could have it on the trickle charger a lot, just to see if it brings a bit more life into the old battery.

 

[Uwe]

it could potentially mean that I could further procrastinate replacing the A6 battery until spring

Why would you replace a battery in the spring, unless it fails outright? The time to replace a questionable battery is just before the weather gets really cold.

-Uwe-

 

[Eric]

Maybe he doesn't drive the A6 much in the winter. I'm currently pre-rotating my riding mower by the rotating fan/intake because the 7 year old battery can't quite start it from cold otherwise. Plan is to either get a new battery or electric tractor next spring , after the current one sits all winter taking garage space doing nothing.

 

[SaVAGeSoot]

Why would you replace a battery in the spring, unless it fails outright? The time to replace a questionable battery is just before the weather gets really cold.

-Uwe-

Mostly because I can... and just don't want to do it until I'm actually worried that it won't start (which is why there's a booster in the trunk at the moment)

Maybe he doesn't drive the A6 much in the winter.

This is basically the other thing.... the A6 is too low and too nice to drive in our winters up here.... we got about 3 hrs of snowfall last night, so I took it around the block and it was a plow... front lip was clearing the road for everyone ..... not my ideal use case scenario. Its a "3rd" vehicle with only 2 drivers in the household, so it will only be used when snow isn't deep or the odd time when roads are mostly clear and slush free preferably.

So replacing a battery to just basically have it sit most of the time, is less than ideal in my view.

 

[MartinsX]

Yup. That's the proper way to test a battery. There's simply no way a little box like that can load-test one; the energy dissipated would smoke it.

-Uwe-

Here I will disagree a bit
Midtronics is an expert company producing car battery testers/analyzers, chargers etc. Several European car manufacturers use Midtronics testers as an approved tool for dealer networks. (Some re-label it with their own "special tool code", some has custom modified software, but in general it is the same Midtronics battery tester). I have used those for years and I can say only good words about those "little boxes"
I have compared measurements by Midtronics with old school methods - load test for CA/CCA and discharging with fixed load down to 1,8V/cell with timer for capacity. Never more than some % difference.
And test takes only seconds
P.S. Sorry for offtopic

 

[Uwe]

I have compared measurements by Midtronics with old school methods - load test for CA/CCA and discharging with fixed load down to 1,8V/cell with timer for capacity. Never more than some % difference.

I agree that Midtronics is a very reputable brand. But I'm scratching my head how that is possible. To do a proper load or capacity test, the energy has to go somewhere, doesn't it?

-Uwe-

 

[davisev5225]

I agree that Midtronics is a very reputable brand. But I'm scratching my head how that is possible. To do a proper load or capacity test, the energy has to go somewhere, doesn't it?

-Uwe-

As I mentioned previously, they use extremely accurate (usually to 3 or 4 decimal places) microprocessors to measure voltage. They don't have to drop 50A (or more) of current like the old-school testers, they can do it with significantly less current, measure the much smaller voltage drop, and calculate accordingly. I still don't personally trust them as a primary measurement, but they are a nice "meter stick" for whether I should go through the extra effort to get a full load test done.

 

[Uwe]

calculate accordingly

A calculated value is not a measured value.

-Uwe-

 

[davisev5225]

A calculated value is not a measured value.

-Uwe-

In this we agree.

 

[MartinsX]

I agree that Midtronics is a very reputable brand. But I'm scratching my head how that is possible. To do a proper load or capacity test, the energy has to go somewhere, doesn't it?

-Uwe-

That's why they had patented their method of measurement

What is a conductance battery tester?

Battery conductance testers work by sending a small current through the battery, and measuring its electrical resistance; they then use this information along with a mathematical model of the battery (, and any data the user may have input) to calculate the battery's performance parameters.

Just found in Google

BTW I've heard about not only "small current" but "signals of different frequencies - to deeply analyze several parameters of the battery"