Battery keeps going flat

[alecmac]

If I leave the car for more than a week or so when on holiday my battery is always flat when we get off the plane (in the rain) and just want to drive home and go to bed.
Its happened four times now after the last time (3) I changed the battery for a new one but low and behold the same after a 7 day break in malta.
How can I check if anything is draining the battery whilst it is not being used.

Is it the alarm system or what am flummoxed!!!

Has anyone had the same problem

[richard@thebrae]

Did you replace/upgrade the radio at any time ? There is an associated problem that causes the battery to go flat.
You can test it by releasing the + terminal and putting a multimeter in series with the battery live terminal and the + lead to measure the current drain.

[alecmac]

Yes about 2 years ago the original radio cd was changed for a mfd2 dvd with a cd changer in the armrest and come to think of it the problems were noticed after this.

What is the fault that makes this happen???

[richard@thebrae]

That is a strong possiblity of being the source of your problem due to a mismatch with the central convienience can interface. Ther is a solutin and a lot more detail in various posts, try a search on these forums :-
http://vwnavi.com/forums/forumdisplay.php?f=50

And this one in particular :-
http://www.my-gti.com/1101/upgrading...er-drain-issue

[-r1ch-]

Took me a couple of weeks to notice that the rear interior light was set to on. Whenever I sat in the car for a bit after I'd stopped or waited for a little while before turning the ignitiion, it'd be a bit sluggish to start. Might be something else but turning this off seems to have helped.

[alecmac]

Guess what !!!!!

I took the car forits MOT and explianed my flat battery problem and gave them the threads from the forums to start to correct the problem and lo and behold.

They refused to look at it and said it could take up to 4 hours of investigation to find the problem so could I pay them £250 up front before they begin to look at it.

And this is a VW dealership next email is to VW. I'll keep you informed.

[shaft-50]

Be interesting to know what your outcome is as i have changed my headunit from rcd to rns after purchase and not sure if my car is suffering from power loss (not left her alone for a week yet to know for def).

Keep us posted.

[newbie09]

oooh i was just about to post about this!!! i have EXACTLY the same problem with my audi a3, Leave it for a week and battery is completely dead

i had the battery replaced as they said it was knackered and then last time i went on holiday last month it did it again. A drain test was carried out whereby they attached a multimetre and then started pulling out fuses to see where the drain was but everything was responding normally apparently

i havent had a new radio put it or anything new put in for that matter so im at a complete loss as to what it is but please keep us posted if you find out what it is!!