XSeries-forum

When will I ever learn?

Background: 2009 XDrive 35d purchased AUC in June 2015, still under warranty. In retrospect, there were always hints of a dying battery with random clock and date resets and radio always on mute when starting, but it got problematic enough to take to local dealer (not the supplier) in October 2016. Given the 'driving style (mainly short runs)' excuse and a bill for wasting their time. It got progressively worse over the winter and this summer, with even long drives barely giving the car 20 minutes with the door open before a dead battery. Checked battery (Bosch Silver <5 years old) and alternator (14.4v when running), although load test not undertaken.

Totally fed up, so checked again, and realised Carly was indicating the registered battery type was 90ah AGM, but the Bosch is lead-acid...

Back to dealer for checking - "you've got the wrong battery fitted, and it is now kaput - that'll be £286 to replace plus our diagnostic fee". Hmm - so the car was supplied AUC with the wrong battery/coding, and they didn't check this in October last year? Apparently not. This is the same dealer that got my sunroof fault so wrong (see other posts) and I should have known.

Anyway, purchased (much) cheaper 110ah lead acid battery, recoded and registered the battery to the car. The coding obviously worked as the running voltage is 13.8 - 14.0, rather than the previous 14.4. I had to buy a new vent tube as whoever had fitted the previous lead acid battery hadn't bothered...

I can only assume that the miscoding (dealer replacing battery prior to AUC and not bothering to re-register?) was pushing too many volts through the battery eventually wearing it out.

Hopefully all fixed (and another lesson learned), although the final proof will be if our 'driving style' flattens it quickly.

BTW - bought on of those hand-held jump starters as a backup over the summer and worked perfectly both times it was needed. Highly recommended.

Just out of interest what hand-held jump starter did you buy.
Do you have a link to one.

Jump starting BMW's can sometimes fry modules.
If you suspect the battery is failing, best to replace it straight away.
Saves a lot of grief in the end.

Unlikely that BMW fitted the battery.  The standard unit is an AGM type hence the higher charging voltage.

Very likely that they failed to check it though as Dealers are far too willing to let the AUC Warranty take the hit rather than them.  Issues with AUC come up regularly and TBH is no better or worse than many other car dealers.

[quote="Alan Gunn"]
Just out of interest what hand-held jump starter did you buy.
Do you have a link to one.
[/quote]

The one I have is a Jackery 18000mah from Amazon, but they appear to be out of stock now.
It was about £45.

[quote="X5Sport"]
Unlikely that BMW fitted the battery.  The standard unit is an AGM type hence the higher charging voltage.

Very likely that they failed to check it though as Dealers are far too willing to let the AUC Warranty take the hit rather than them.  Issues with AUC come up regularly and TBH is no better or worse than many other car dealers.
[/quote]

Probably right. Car is now 8 years old so must have had a change at some point (given age of battery, about 4.5 years ago) by a non-BMW person (Carly has no record of a previous battery change, so many shortcuts taken).

It’s probably fair to add that unless you frequent this sort of Forum you probably would remain unaware of this coding lark.  I only discovered that my 2015 Škoda Superb 3 has it too after it failed a few weeks ago at 04:00!  >:( 

Previous models don’t.

It’s all a conspiracy to keep car repairs in the main Dealers hands I tell you........... :doctor:

I had a similar issue that the "specialist" put a non agm in one which kept going flat

is there any point buying AUC from BMW?

[quote="mac1986"]
is there any point buying AUC from BMW?
[/quote]
I guess it depends on your expectations. If you work on the assumption that main dealer 'technicians' are the best people out there for diagnosing and fixing your car then I think you're in for a lot of disappointment. In fact, I work on the assumption that the main dealer is the last place I would take my car for repairs if I'm paying for them - they will just follow the computerised guided fault finding which will tell them to replace (not repair) a series of parts in the hope of eventually finding the one causing the problem. Not an approach I want to fund. This lack of mechanical expertise means that I wouldn't really put a great deal of faith in their inspection process, which probably just involves a diagnostic scan followed by a visual check of some key components.

However the 12 month unlimited dealer warranty, although not perfect, is probably the best warranty you can get. So if you value having a warranty then AUC might be worth the premium.

Realistically, with AUC you're not buying a better car, you're buying the support of the dealer for the next 12 months if something goes wrong. Not worth it to me, but everyone has different priorities.