AGM battery for older vehicles?

I have an Audi A6 4B C5, engine code AWX, manufactured in 2004. The original battery is starting to wear out.
Can I simply switch to an AGM battery, or is my car not designed for it?
It worked perfectly in my motorcycle; the battery indicates a maximum charging voltage of 14.4V.
Is it the same with car batteries?
Greetings.
Benno.

Why do you want to?

The AGM battery in the 3C is almost twice as expensive as a standard lead-calcium battery.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Yes, that's correct. I'm very impressed with the Startpower. Also, I do a lot of short-distance driving. An AGM battery simply charges faster and more efficiently in those situations.

It usually works without problems if the installation dimensions are correct and the positive and negative terminals are in the right place.

Damn.

I wish I had known...

I actually bought a new one, another lead-calcium battery.

Recently, I noticed that the BlueMotion models (specifically, the current generation Passat B7 TDI) always have an AGM battery. I only knew them as a second battery located in the interior of the wagon variant, if it has a standing heater.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

dieselmartin wrote:

Manure. I wish I had known... I actually bought a new one, another lead-calcium battery. Recently, I noticed that the BlueMotion models (specifically, the current generation Passat B7 TDI) always have an AGM battery. I only knew them as a second battery located in the interior of the wagon variant, if it has a standing heater. m;

Um, how am I supposed to understand you? Are you saying that above, you mean that something is too expensive for me, and now you regret buying the calcium supplement?

"Of course, the battery must be compatible." But I read the following:
The BEM code should be encoded into the energy management system of newer VW AUDI models (approximately from 2004 onwards) to ensure that the battery is optimally charged throughout its lifespan.
What is the BEM code, or does my car already have it?

T3Surfer wrote:

dieselmartin wrote: Crap. I wish I had known... I actually bought a new one, another lead-calcium battery. Recently, I noticed that the BlueMotion models (specifically, the current generation Passat B7 TDI) always have an AGM battery. I only knew them as a second battery located in the interior of the wagon variant, if it has a standing heater. m; Um, how am I supposed to understand you? Are you saying that above, you mean it's too expensive for me, and now you regret buying the calcium supplement?

Well, until now, I thought that AGMs only had this advantage of "interior safety."
But even if they "start better," my money tends to disappear quickly.

The BMR, unfortunately, isn't a great starting option due to its excellent speed threshold .

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Benno wrote:

...does my car have that already?

No, not until the A6 4F (C6).

So, my NoName 95Ah lead-acid battery has a 850A starting current.
The comparable Varta AGM has a CCA of 880A.

Based on the amount of electricity, I don't see any difference there.
However, what the AGM does better is that it's more dynamic/faster.

That's not really necessary when you're just starting out.
The starter motor runs for a relatively long time.

With AGM batteries, you often encounter the problem that the alternator provides an incorrect charging voltage.

Hello everyone,

I've been looking for a new battery for a few days now. Normally, I replace any broken OEM parts with better ones (if possible). When it comes to batteries, I'm not sure what to do.

I'm undecided between the following batteries:
Banner PowerBull P7209 72Ah - Rank 2 - ADAC 2011 -> approximately €90.
Moll M3 plus K2 71Ah - Rank 1 - ADAC 2011 -> approximately €120.

Exide AGM EK700 70Ah battery -> €135.
Banner Running Bull AGM battery, 70Ah - €160.

Can anyone tell me if I can use an AGM battery in my Fabia?

Quote:

Und bei der AGM Batterie hat man eigentlich immer das Problem dass die LiMa die falsche Ladespannung liefert.

My multimeter shows that my Fabia Lima consistently has a charging voltage of 14.8 volts.
It's a Bosch 120A alternator (LiMa). What would be the correct charging voltage?


Do they really perform as well as their manufacturers claim? I couldn't find any comparison tests of AGM vs. standard batteries anywhere online. Both Banner and Exide advertise a threefold cycle life and higher starting currents. This would almost double the lifespan, which would eventually offset the higher price (from an overall economic perspective).

Long-term experience?

Benno wrote:

The BEM code should be encoded into the energy management system of newer VW AUDI models (approximately from 2004 onwards) to ensure that the battery is optimally charged throughout its lifespan. Was ist der BEM Code bzw. hat mein Auto das schon ?

Essentially, this is a way for Audi/VW to make money. The modern battery management system learns about the battery using a Battery Emulation Model (BEM) code. In effect, it simulates the aging process.
As the battery ages and reaches certain "thresholds," the vehicle's onboard electronics will switch off some consumers – until the battery is fully charged again. Furthermore, the system monitors for a consistent positive energy balance.

If you don't enter a Battery Management System (BMS) code and simply install a "suitable" battery, you're essentially doing it a favor. For example, if you frequently drive short distances and it's -20°C the next morning, it might not activate the "coming home" light feature. However, you can easily encode the BMS code from an original battery. This clears the learned values and registers the new battery as a specific "xyz" type.
If you don't install a remanufactured battery with completely different specifications, it will likely be within the same range of variation that the suppliers also produce for the "OEM batteries."


In short:
Even if your Audi is already affected, you can't do much worse than what might happen in other cars (by buying inappropriate batteries or using incorrect values or techniques). The worst that could happen is that your Audi might not fully utilize all of its comfort features under certain operating conditions.


Hi FabiaCombiTDI,

My multimeter shows a constant charging voltage of 14.8 volts for my Fabia Lima.


An AGM battery must never be charged above 14.4V.
Ideally, they should be temperature compensated (-0.24V per 10°C). Only then will the batteries achieve the long lifespan that manufacturers advertise.

The AGM battery will work in your Fabia, but it won't last very long.
You could install a charger specifically designed for AGM batteries, which would charge the battery with the correct charging profile. However, these chargers can be just as expensive as a good lead-acid battery.

Lead-acid batteries are significantly more robust, do not require temperature compensation, and can tolerate higher charging voltages (up to 15V) without issues.

Quote:

An AGM battery must never be charged above 14.4V. The AGM battery will work in your Fabia, but it won't last very long. You could install a charger specifically designed for AGM batteries, which would charge the battery with the correct charging profile, but it would also cost as much as a good lead-acid battery

.

And what are all those AGM batteries doing in the trunk of a Passat Variant?

Die werden, sobald der Motor läuft, ans Bordnetz geklemmt ... UNREGULATED.
Unless you call 3m 4mm² "regulation" .

On the other hand, I've seen that both the 3C and 1K models consistently maintain a verschandeln upper limit of 14.4 volts (both with the same 180A alternator).

I'm not even going to say that it works well.

However, if arguments are being made based on advertising claims that AGM batteries last twice as long, it must also be clearly stated that they will only potentially last that long under ideal conditions.

Therefore, the economic argument has been refuted.
Unless you invest again in an expensive charging regulator.

Thank you for your input.

Banner nennt als Obergrenze 14.8 Volt für die Running Bull. Exide stellt sich was die Ladespannung angeht komplett tod. Die sagen man kann problemlos AGM und ECM in herkömmliche Fahrzeuge verbauen, nur sollten diese nicht in allzu heißen Umgebungen hausen. (Motorraum) Dieselmotoren werden prinzipiell aber auch mit AGM ausgestattet. zb. A3 oder Polo 6R 1.6TDI. Dort sitzen die Motoren im Motorraum. Large power plants, such as those with a 2.0 TFSI engine, often have the AGM battery located in the trunk.
Source: http://www.exide-automotive.de/Micro-Hybrid/Content/MH_Fahrzeugzuordnung.html

For the voltage issue, I will run some tests with a multimeter around the area tomorrow. The family has: a 320d from 2009 and a Polo 6R 1.6TDI from 2010 - both are equipped with AGM batteries. The BMW even has an Exide battery in it, and I'm considering getting its smaller brother .

As often happens, this isn't really about being particularly clever or trying to make a battery last for 14 years. Rather, it's about me simply KNOWING what's going on. There isn't much information available online about this topic. And when there is, it's usually in sailing boat forums, which discuss entirely different use cases for AGM batteries.


Hi FabiaCombiTDI,

The two types of vehicles you mentioned likely have a start-stop system.

And that's precisely why the Passat has the AGM battery located where it always has been: in the engine compartment.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.