Audi A4 B8 battery drainage issue

[Kyle Peachey]

Hi 

I need some help with my audi a4 b8 2009 diesel 

For some reason my audi's battery is draining rather quickly i've bought a cheap battery just to use as a test to see if its just my old battery thats gone and needs replacing or if something is draining it. ive checked fuses and nothing seems to be a miss.

Has anyone had this problem before ?

Is there a fix?

Is it majorly important that the battery is coded ? 

Any help would be greatly appreciated.   

[Kyle Peachey]

hi yes the original battery was at 52% when it was last tested which was just after jumping the car i believe.

the cheap battery is same spec as the original battery. 

alternator was tested and i was told is working as it should.

how will the battery hard reset help? 

[Kyle Peachey]

would a hard reset cause any issues with a stage 1 remap ? 

thanks for your replies much appreciated 

[Kyle Peachey]

ok thank you for your help i will look into replacing VSR thanks 

[Magnet]

Hello Kyle,

To keep it simple, you need to measure any residual discharge at the battery once the car has been locked up, the alarm set, and the whole system has gone to ‘sleep’. 
As a ball park figure, you would  be looking for a drain in excess of around 50mA, if your battery is being discharged via. a parasitic drain. 
If it has been established that the drain is greater than that, then it becomes a laborious task of removing each fuse in turn until the offending circuit is found. 
Yes, you could DIY it if you have the correct meters to do it, but it may be one of those tasks left to a a trusted local autoelectrician. 
Kind regards,

Gareth. 
p.s. Any of this maybe influenced by water/ moisture ingress. 
 

[Kyle Peachey]

thank you magnet i will look into all of the above 

 

[Magnet]

Hello Jason,

Thanks for your latest post, stating that the offending component is the Voltage Stabiliser Regulator fitted to the poster’s vehicle. 
If Kyle actually replaces this component and the issue isn’t solved, will you be prepared to fully reimburse him his outlay? 
Kind regards,

Gareth. 

[Stevey Y]

6 hours ago, Magnet said:

Hello Jason,

Thanks for your latest post, stating that the offending component is the Voltage Stabiliser Regulator fitted to the poster’s vehicle. 
If Kyle actually replaces this component and the issue isn’t solved, will you be prepared to fully reimburse him his outlay? 
Kind regards,

Gareth. 

Hi a hard reset used to work on old Fords and most likely on Audis fry the BEM module which wont be the source of a parasitic drain, the idea of putting a new BEM number in is to let the monitor know it is dealing with a new battery therefore it will charge at a lower rate so it wont cook your new battery, as for losing the map, the ECU on a car is one of the more expensive items, they don't fit ECUs that are specific to one model instead they build a unit with multiple map layers to accommodate the different engine types I.E. 1.0, 2.0 etc if you unplug the ECU you still wont lose the map as its embedded over your existing map from factory, thats why if you want the map removed you have to go back to the map originator to have it removed.