A4 Avant 2009 - Battery Location

[mghassey]

Hi - I have the 1.8TFSI A4 Avant, 2009 model.
Recently had to jump start my wifes Polo and could not find the battery in the A4 anywhere!!
Anybody tell me where it is please for future reference.
The handbook doesn't tell me and only mentions the two points for charging & jump starting the A4 with the comment that to jump another car I should use the engine block not the -ve terminal (also easier said than done!!).
Cheers
Mike

[xtremist]

I think it's in the boot under the spare tyre (admitidly itv was dark when i changed the wheel, so might of been seeing things)

[adrianwalker]

I think it's in the boot under the spare tyre (admitidly itv was dark when i changed the wheel, so might of been seeing things)

It's definitely in the boot and IMHO make it easier and safer to jump start another car.

[mghassey]

Thanks Fella's -

IMHO ??

[simfin]

Thanks Fella's -

IMHO ??


IMHO ?? = In My Honest Opinion

[adrianwalker]

IMHO ?? = In My Honest Opinion

or "humble"

[mghassey]

Aaah!
Should have got that!
But I totally agree though!

[Sportwag]

Happened to me in Dublin last year when a guy approached asking for help to jump start his car. I pulled the bonnet and we both stood and looked blankly at the engine before he headed off to ask someone else. At the time I was quite relieved it couldn't be found tbh.

[Zenerdiode]

It's definitely in the boot and IMHO make it easier and safer to jump start another car.

You mean the terminals in the bonnet area make it easier to jump start another car :confused: :)

You should not use a direct connection to the battery in the boot:


Power taken to jump the flat vehicle will not be drawn through the Battery Condition Monitor and therefore the actual battery charge will be less than what the BCM thinks it is. This may lead to conditioning/charging problems.
The BCM is physically connected to/part of the battery negative terminal. It's small and the potential to damage it is high.
The positive terminal has the 'Battery Disconnect' device incorporated in it. This is a pyrotechnic device that is triggered by the Airbag module in the event of an accident to immediately and physically disconnect the battery. You don't want wayward connection sparks/electrical noise to deploy this accidentally.

Although connecting to part of the engine block for the flat vehicle is sometimes a pain, the reason is often not stressed highly enough. When flat; and immediately when the leads are connected, electrolysis of the water in the battery acid starts taking place. This releases Hydrogen and Oxygen in the perfect explosive proportions. Depending on the venting arrangements on the battery, the sparks from the final connection are enough to ignite the mixture and the battery explodes. This is will burst the battery case and drench you (but more importantly - the car ;)) in Sulphuric Acid.

[Zafi]

Good comments on jump starting.

The last connection you make must be to the vehicle with the good battery, this will avoid creating sparks where there is likely to be hydrogen present.

I have had one employee suffer permanent ear damage and temporary eye damage as a result of an exploding battery. He washed his eyes out in a dirty puddle, otherwise his injuries could have been worse.

[mghassey]

Many thanks to everyone for their attention to this, and some very useful information.
I now have the answer to my actual question, where's the battery? - in the boot under the (Stupid!) skinny spare wheel.
The discussion on the correct procedure fo jump starting another vehicle is certainly interesting.
In the owners handbook Audi state that you shoul use the +ve & -ve terminals provided under the bonnet to charge the battery or jump start the Audi.
But to jump start another vehicle you should use the +ve terminal and the engine block or solid metal connection NOT the -ve Terminal.
As I noted before, it's not straight forward to find a metal part of the engine that you can safely reach and then attach the jump / booster leads to!
As a total aside from interest I put a meter across the +ve & -ve terminals and got a permanent 12v even with the ignition off. I then measured the resistance between the -ve terminal & the engine block and got zero resistance in both directions (i.e. -ve of meter to block +ve to terminal and vice versa). To me this IMPLIES that the -ve terminal is in fact a straigh mechanical connection to the "chassis" / engine block and inspecting it that is certainly how it seems to look.
However, who can tell what magic boxes these folk come up with! Far tto clever by half I'm afraid (and I'm a lifelong electronics engineer but cut my motoring teeth on the good old ford side valves! Strip down, refurb & rebuild in a weekend!)

Again many thanks for all the interest and excellent advice.

Mike