AFAIK for proper battery management and longevity it must be coded, you can source the right battery for IRO £150 by shopping around and can probably code it with the cheap version of OBD Eleven (about £50?), perhaps others on the forum can advise on that, useful to have a diagnostics/coding tool anyway.

 

go for the same battery type for technology (agm), a/h (70), dimensions etc, coding it is a must (with VCDS for sure, maybe even OBD11), if the battery hasn't the BEM sticker, just increase the last digit of the current serial number and job is done, more complicate to explain than doing, look for some tutorial on YouTube

you can buy the OEM battery at a much cheaper price outside of Audi dealers net
https://www.amazon.it/dp/B00CEBBBCE/?co ... _lig_dp_it

 

Thanks guys

 

Hey man, I'll paste my usual reply below to help you and others understand the point of coding, because I think it's actually a really cool system:

If you've put in an AGM battery, it should be set to fleece. Apparently this is a "bad translation" of the fleece/wool-looking material in AGM batteries and the German word used for them. More importantly, and leading to my next thought, the resting voltage of the battery when set to "fleece" is 12.8, which is exactly what you want for AGM.

Keeping a battery at 14V like in the old days is terrible for batteries, especially newer designs like AGM. Most modern cars (like any modern Audi) have a "accessory mild hybrid" system in that the ECU tries to only run the alternator and recharge if the driver is braking or coasting (aka sort of like regenerative braking). This means the alternator isn't loading the engine when trying to accelerate, which makes things faster and emissions lower. It also means the power needed to restart the engine after start/stop is basically "free" energy gained during braking when you're wasting it anyway.

The important part to maximize this process, is that the ECU needs to know the state of charge of the battery at all times to keep from under or over charging it. This depends on the overall Ah capacity of the battery and its age (hence coding overall capacity and resetting the "age" timer with a new serial number). Additionally, different battery chemistries need to be held at different resting voltages. Normal flooded lead acid like to be held at 12.6 V. AGM needs 12.8 V. If you switch from a flooded cell to an AGM battery and don't change the coding, the new AGM will always be undercharged at 12.6 V, which can in many cases literally half the overall life of the battery. If you treat them correctly (correct resting voltage), AGM can last 2-3X as long as traditional flooded cell.

 

good recap!

 

Just thought I would add to this old thread.
Over the last few weeks I have had numerous dash alarms and warnings flash up on two separate ocassions.
After the first ocassion, my local garage implied its an indication the battery performance is low as these system are very sensative to low voltage even though the car starts no problem.
His tester indicated the battery was only 40% charged and he loaned me his AGM trickle charger (as my CTEK does not have an AGM option). It charged to 100% fairly quickly, I cleared the alarms etc then 2 weeks later they all came back.
I have an iCarsoft VAWS V2.0 for reading and clearing codes, lamp resets etc etc.
The battery info says the fitted battery is a JCB, battery itself is a Varta with what looks like an OE sticker stating JCB and its serial number.
The -ve post is stamped 69 15 which makes me think its the original battery, now 10 years old.
I have purchased a Bosch 80Ah AGM battery from Tayna Batteries, small discount and delivery for £135, arriving this afternoon.
My iCarsoft OBD box should allow me to register the new battery.
If the iCarsoft coding of the battery works then all told its a considerable saving on prices quoted in previous posts, especially as the previous posts are now over 4 years old.
I have an iCarsoft for both my Porsche Boxster and the TT and have paid for themselves several times over.

 

Good info. My TTS battery is 10 years old now and i'm just waiting for it to go.

 

I managed to change my battery and register it through my iCarsoft box.
With changing the battery, all manor of alarms then flashed up on the dash.
These then cleared when first driving the car but the original ones re-appeared after clearing them.
I started another thread on this a few weeks ago and a few members pointed out that it maybe an ABS fault.
Returned to my local garage just now, and with their OBD box and live readings fromm the ABS sensors while the car is driving, right rear sensor not sending out a signal and indicated a mechanical fault which they suspect to be the "magnetic ring".
So although my battery was 10 years old and its charge was down so probably worthwhile replacing it, it seems the central fault was an ABS one.
However, was told, the magnetic ring is all integral to the wheel hub and bearing.

 

Has there been much improvement on these batteries over the last 10 years? As lasting that long (10 years) is impressive.

Will the next battery last 15/20 years? 😂

 

Has there been much improvement on these batteries over the last 10 years? As lasting that long (10 years) is impressive.

Will the next battery last 15/20 years? 😂

I dont think lead acid batteries have much development, perhaps we will see Li-ion or Li-Po in the future.