Battery drain overnight clues to what it could be

[Colin Anderton3]

hello I have an audi a4 b6 avant 2.5tdi suddenly the battery has started to drain overnight any clues as to what it could be, there are no lights on or anything else I can see any advice would be welcome cheers from Colin

 

[vr6gordy]

Stick battery on charge and see if it goes flat again my guess is your battery is knackered

 

[Colin Anderton3]

thanks for the reply, yes done that, I have a spare battery and that was fully charged put that on the car and the next morning the battery was too low to start the car, the original battery I took it to my trusted Audi dealer and they put it on charge and when checked today said the battery checks ok, the original battery is now back on the car and it has dropped .6 of a volt in about 4 hours so will see was has happend in the morning cheers from Colin

 

[kanecullen89]

I'd still guess at the battery being the fault.

Have you scanned the car with vcds?
If the current being drawn while the car is shutdown is too high then an error will be logged.
It should also log an active power management (when the non essential components are disabled to save enough juice for the engine to start)

 

[john777w]

Remove the battery earth, connect an amp meter between the earth lead & battery post. Run the meter to the outside of the car so you can close the bonnet, lock the car & wait for a few minutes for everything to close down, you should be able to see any currant draw. DON'T START THE CAR you will fry the meter!

 

[Colin Anderton3]

thanks guys will do what you suggest I shall post the results when checked, I have not been out to the car this morning so will go shortly and check, cheers from Colin