A6 3.0T battery question

[cuerna]

Hello,

I recently bought an A6 2012 3.0t , I noticed she struggles a tiny bit during the first start in the morning. I checked the battery and noticed doesn't have the original battery, dealer installed an AC DELCO battery ( smaller than original physical and have 615 CCA 110 RC 70 AH) . I don't think this is the best replacement for this vehicle since my car has a lot of electronics, heated steering wheel, cooling and heated seats etc.

Will this battery damaged anything if a keep using it? Like the computer or any other electronics.
Also noticed when I bought the car that the original audi battery was laying on the floor, I asked them about it and they let me take it with me, but they didn't give me much information about it. I noticed the parameters are very different compared with the Ac Delco one.
Unfortunately the audi battery won't take a charge (is dead and drained) when I tried to charge it. It think there is something wrong , I know it is not too old because it has a sticker on it with the date 8/20.


Thanks in advance!!

[RAF_S7]

Any replacement battery should be the same size (or larger) than the original battery, which is likely why it’s struggling (though to be fair, if the car is parked outside, and the temperature is low, most batteries may take a few extra turns to start the car…)

What was the AH of the Audi battery that was in the car?

[cuerna]

The audi battery has these parameters:
12V 110 AH 520 A DIN
850 A

[Audisthesia]

You can put an H9 in these cars.

[Alabama]

You can put an H9 in these cars.

I'm not sure AC Delco makes an H9. They do make an H8 AGM which is what the dealer should have used if they only have AC Delco. Looks like the OEM part number is 000915105DLDSP, not sure what the physical size is. From lots of AZ posts, these cars are pretty sensitive to variations in voltage, so that would be the concern if the installed battery is too small. Systems may shut down and error codes thrown, though it seems like most of the time nothing is permanently damaged; replacing the battery with a proper sized one solves the problem. A good battery dealer (for example, Interstate battery distributor) may have industrial strength charging equipment that might be able to resurrect the Audi battery with the 8/20 manufacture date. Worth a try. Otherwise, maybe go back to the car dealer and ask them to take back the small AC Delco and give you the H8 AGM model (or some other manufacturer's H9 as Audisthesia recommends).