# DIY: Battery Replacement A3 3.2 Quattro



## MillerMav (Sep 7, 2012)

Yes; I know this should be a pretty "Duh" type of thing but since this forum severely lacks DIY's that an everyday driver may need I figured I would write this up. 

For those who do not know the battery for the 3.2 VR6 Audi A3 is located in the trunk. It is set low on the passenger side so it does actually offer a little weight balance to the driver if you're into that sort of thing. It does make it a bit more of a task to change than a standard battery located in the engine bay.

1. Lift up the carpet covering the spare tire area in the hatch/boot/trunk. (No picture; this one is easy)

2. Remove the spare tire by turning the large knob in the center of the spare rim. Place it aside and lift the tire out of the well. FYI: this is a good time to check the air pressure in your spare!










3. Remove the foam block located on the right hand side of the area closest to you. It pulls up slightly and then to the left to remove. It should not be difficult to remove.










4. Now its time to get a couple tools. You will need an 8mm triple square socket to remove the bolts holding the cover on. This is a black sheet metal cover that sits over the battery. If you have a small impact driver it makes this job quite fast; if your doing it by hand it will take a few minutes to get all of the bolts out. Remove the cover and set it aside.



















5. Remove the foam block covering the battery. 










6. Locate the battery vent and remove the vent from the battery. Pull it gently toward you to remove it; it may require some slight twisting back and forth to break it free depending on how long its been on. Do not pull it off of the car; just remove it from the battery.










7. Disconnect the negative terminal first then the positive terminal. I used the little net pocket on the right to hold the negative terminal and keep it out of the way. Unlike a lot of vehicles on the road the positive wire is clear/silver but the negative cable is still black



















8. Remove old battery and replace with new. Reverse steps 7-1 to place new battery. 

Keep in mind it is a good idea to attach the positive cable first then the negative. This removes a lot of potential for "surges" or slight "arc'ing". Also when replacing the metal cover make sure to not pinch the cables (there is a relief in the place that they line up with) and replace the bolts in a criss-cross pattern so you do not potentially warp the plate.


----------



## krazyboi (May 19, 2004)

WTF, I didn't know we had a vent hose like that. Someone must've tossed mine at the shop when they replaced my battery 

Although, I do have a AGM battery which I don't think needs a vent anyways.


----------



## neu318 (Feb 18, 2003)

Thanks for the DIY, I may have to change my battery soon as it takes a little to crank in the mornings. By the way, I thought the battery was supposed to have some sort of device that cuts off power to the car after an accident.


----------



## SilverSquirrel (Jul 24, 2006)

note that the new batteries have a vent hole on each end. Both holes vent the whole battery.

You insert the vent pipe into one, this vents battery gasses out the bottom of the car. 

The other hole needs to be plugged. Use the plug from the old battery. or: My Advance Auto AGM came with a plug molded onto the positive terminal protective cover. Just break it off and plug it in the other hole. this way, gas wont vent into the battery compartment.

Also, when you put the spare back, dont crank the snot out of the hold down knob. It is audi plastic, and will break. ask me how I know.


----------



## neu318 (Feb 18, 2003)

SilverSquirrel said:


> note that the new batteries have a vent hole on each end. Both holes vent the whole battery.
> 
> You insert the vent pipe into one, this vents battery gasses out the bottom of the car.
> 
> ...



How do you know?




LOL, just kidding.


----------



## Ponto (Jan 11, 2012)

SilverSquirrel said:


> Also, when you put the spare back, dont crank the snot out of the hold down knob. It is audi plastic, and will break. ask me how I know.


So true...


----------



## krazyboi (May 19, 2004)

SilverSquirrel said:


> The other hole needs to be plugged. Use the plug from the old battery. or: My Advance Auto AGM came with a plug molded onto the positive terminal protective cover. Just break it off and plug it in the other hole. this way, gas wont vent into the battery compartment.


School me on this, wondering if this is perhaps a reason why I'm getting trouble with starting sometimes?!?! My other hole isn't plugged. Yes, that was intentional.


----------



## SilverSquirrel (Jul 24, 2006)

krazyboi said:


> School me on this, wondering if this is perhaps a reason why I'm getting trouble with starting sometimes?!?! My other hole isn't plugged. Yes, that was intentional.


I would say no, unless of course your battery is bad. And even a new battery, if not properly charged by the alternator/regulator, will not last very long. Correct charging voltage is important to battery life. bad grounds anywhere in the path from alternator to battery will do that. check your grounds.

If you dont have your vents plugged at all, the battery gas just wanders into the trunk and corrodes stuff. 

"Generally, Volkswagen factory-installed
batteries are equipped with one vent
hole at each side. One must always be
sealed to ensure that gas is only vented
at the side with vent tube attached.
If both vent holes are sealed, the battery
can explode under pressure. A plug must
be removed from one of the vent holes
according to the installation instructions
for Volkswagen OEM batteries."


*Interior or Luggage Compartment
Location*

If the battery is located inside the vehicle, a wet
battery with optimized tilt angle properties, or an
AGM battery with anti-leak protection is used.
Batteries installed on the inside of the vehicle are
also equipped with a gas vent hose to prevent injury
from leaking battery acid in the event of a rollover
accident with the vehicle coming to rest on its roof.
Tilt angle optimized or anti-leak batteries minimizes
the risk of acid burns.

When replacing a battery choose one with
Volkswagen factory-installed battery features

Ensure the gas vent hose is inserted into the
central gas vent opening of the battery


----------



## krazyboi (May 19, 2004)

Thanks Squirrel! Now, to find a OEM vent hose. (I rigged one out of a rubber tube a while back since I figured it needed a hose).


----------



## npace (Sep 3, 2012)

Sorry for the necro-bump. Can anyone with a 3.2 provide me with a pic and explanation of where the negative battery connects on the car? Also, if anyone has a part number for the battery vent hose, that would be great. TIA.


----------



## CABruce (Jun 10, 2021)

MillerMav said:


> Yes; I know this should be a pretty "Duh" type of thing but since this forum severely lacks DIY's that an everyday driver may need I figured I would write this up.
> 
> For those who do not know the battery for the 3.2 VR6 Audi A3 is located in the trunk. It is set low on the passenger side so it does actually offer a little weight balance to the driver if you're into that sort of thing. It does make it a bit more of a task to change than a standard battery located in the engine bay.
> 
> ...


Is there anything special required when changing the battery; is it as easy and remove and reinstall? Do I need a VAG code reader or programmer or whatever; do I need the radio code as well?
Thanks.
Sorry if these are stupid questions.


----------



## kgw (May 1, 2008)

As long as you simply take out one battery, and replace it with the new one in a short period of time, the settings will remain.


----------

