Battery keeps dying - A4

[Grimspoon]

So about a month ago my battery died on my Audi A4 B7, as you do I went off and got a new one fitted thinking the battery had just seen its day. 2 weeks later the new battery dies, car won't start. Anyway I jump it and take it back and they replace the battery. Now this morning, same story.

I thought at first I had just got a dodgey battery, but clearly its something wrong with the car. Anyone have seen or heard of this?

 

[The_Unbeliever]

Any accessories (radio, lights etc) left on overnight?

Is the battery charging when the engine is running? Have the battery place checked out the charge current from the alternator?

 

[Grimspoon]

Any accessories (radio, lights etc) left on overnight?

Is the battery charging when the engine is running? Have the battery place checked out the charge current from the alternator?

Nope no accessories on, checked that the last time, actually thought the wife had left one of the doors ajar and the light killed the battery.

They checked the alternator last time and they said it was all fine, the reading that came out of the machine was "replace battery".

 

[chrisc]

If the alternator is delivering sufficient current then there might be a fault with the engine management system. Their diagnostic machine should be able to guide you towards the cause

 

[Cool E]

alternator faulty. Have it checked at a dealer.

 

[Grimspoon]

If the alternator is delivering sufficient current then there might be a fault with the engine management system. Their diagnostic machine should be able to guide you towards the cause

Cool thanks. I am going to send it to my mechanic, he has all the diagnostic tools so hopefully he can sort it out. The car has been acting strange, first the bluetooth module stopped working, then it started working again and is now dead. I noticed sometimes when the car is in P the revs climb up to 1.5 rpm for no reason. Something is not lekker.

 

[spiderz]

What make of battery?
Had a Sabat that died every 6 months or less..

 

[Grimspoon]

What make of battery?
Had a Sabat that died every 6 months or less..

Excide. That's all High Q sell now apparently, they say they are better than Willard.

 

[RazedInBlack]

I doubt its the battery so I'd go with what Chris said.

 

[Grimspoon]

After reading up, it seems a few people have had a similar issue where the telephone module is faulty and is causing the battery drain. Given that my telephone module has packed in, I am willing to bet this is the issue.

 

[chrisc]

Well, he had the alternator checked which is not rocket science. There is something drawing 1/2 amp or worse, so the telephone module may be the culprit since the current limiting on this circuit is in the region of 3 amps

 

[chrisc]

Cool thanks. I am going to send it to my mechanic, he has all the diagnostic tools so hopefully he can sort it out. The car has been acting strange, first the bluetooth module stopped working, then it started working again and is now dead. I noticed sometimes when the car is in P the revs climb up to 1.5 rpm for no reason. Something is not lekker.

Worst case - trade it in... Buy a Japanese car

 

[ChocolateBadger]

Loose ground wire. Same happened on my jeep.

 

[Grimspoon]

Worst case - trade it in... Buy a Japanese car

lol, not a bad idea.

Loose ground wire. Same happened on my jeep.

Yeah could be. Only thing swinging me towards the bluetooth module being the culprit is there are other people that have had this exact issue.

Anyway, she is at the doctor now so I will wait and see what the prognosis is.

 

[poffle]

GPS tracker unit? These guys also drain moerse battery when theirs fails.

 

[Grimspoon]

GPS tracker unit? These guys also drain moerse battery when theirs fails.

Yeah was my first thought, had a mate check on his side if one was ever fitted and came up empty. So no tracking unit.

 

[Grimspoon]

So the diagnosis is the following: There is in fact a tracking unit in the car that is drawing about 0.8 amps and as I suspected the faulty bluetooth module is also drawing power, about 1amp. And that is the cause of the dead battery.

So ya, need to get the tracking unit removed and get a new bluetooth module. Joy.

 

[Rickster]

Here is a nice check list:

1. Alternater check: Start the car, put a multi-meter on the battery and if it reads 13.5 to 14.5 Volts then its working (make sure jumpers/booster pack is disconnected and all electricals are off such as Fan,AC,radio,lights.

2. Battery draw: Go to a spares shop and buy a test light (or make your own). Disconnect the Negative wire on the battery and connect the one end of the test light to the Negative and the other end to the negative on the battery. If the light on the test light lights up you have an electrical draw on the battery (same thing as leaving the radio or lights on). Take your car to an auto electrician NB: make sure the doors are closed and the ignition is OFF before doing the test.