Battery replacement - Start-Stop

[capncook]

Hi,
I have a 2011 A3 1.6 TDI with Start-Stop. The car came the original Lead-Acid battery (the label is identical to that shown here P/N: 5K0 915 105 G) which now won't start the car. The Start-Stop functionality hasn't worked for a number of years (see below). Therefore I want to know:

1. If I replace the battery with a similar part (e.g. YBX3096), will the start-stop functionality come back alive?
2. For start-stop to function again, is recoding required or is this battery type dependant?
3. If start-stop will come back, am I better with an EFB or AGM type battery (e.g Bosch )(I gather the OEM P/N is 000 915 105 CC)?
4. Is the expense of AGM worth it vs EFB?

Notes

• My experience with old batteries is that once they go dead, recharging them never really work and you need to replace them
• From when I bought the car (2018), the start-stop functionality never really worked frequently and hasn't functioned at all for about 3 yrs. I was doing many motorway miles so it didn't matter. That's changed now

 

[Gazwould]

Leave it , Stop Strain is an abomination .

 

[capncook]

Not sure this is an option - Strangely, I called Audi, they're offering a smaller current battery than what is in it.....

 

[TorqueyDale]

My 2012 2.0 TDi factory fitted battery finally died at the start of July 2020.
My stop-start gave up approx. 1 month prior to the car giving low voltage warnings upon starting the car.

I opted for an aftermarket replacement, similar to the one you've linked on auto doc (Yuasa HSB096). Yuasa seem to get a good write up from the electrical boffins.
As for the comparison between AGM and EFB, I opted against this given the 5 year guarantee which came with the battery anyway.
You're right that if the car measures a voltage below the threshold set, then stop-start won't work until it recovers above this point.

I'm curious to know how you've got on with the problem?

 

[capncook]

So I took the original out and put it on a trickle charger for a few hours. It started drawing about 4 amps but decreased to about 1.5 after an hour. Left it there for about 3-4 hours. Popped it back in and went to get the replacement. Stopped at the first set of traffic lights and the engine cuts out....You can imagine my shock with this recommencing after 3 yrs.

Went a Varta AGM in the end as this was what they had and the reviews seem pretty good. They recoded using a Yu-Fit battery encoder and we are all good. Stop-Start functions nicely, albeit I need a run to regen the DPF.

Strangely, I called Audi about this and they quoted me a different battery to what the did before and to what was in the car. They also wouldn't release the part number

 

[nluk100]

Glad you got it sorted. Audi can be funny buggers at times. I read a post recently where someone fitted a new battery themselves and went to Audi to get it re-coded. They wanted £180 to re-code it! £35 yes, but £180??