Battery or alternator?

Meatball · 30 Jun 2016 at 17:31

slick rick said:
Does your car have stop start? If so that could indicate that the wrong battery is fitted as I would expect an AGM battery to be fitted to a car with stop start. Did they tell you what battery is supposed to be fitted as there are a few choices that can be selected via coding?

No stop/start, it's an early R56 model and I have a blank switch where the stop/start button should be.

The garage have just got back with a quote:

Part: 61216924021 - Original BMW AGM Battery (£132)

The alternator is either of these two models, they can't tell until they've removed it apparently:
Part: 61216924021 - Alternator 150a/h (£560.98)
Part: 12317619254 - Alternator 120a/h (£120.95)

Ouch!

Garage said:
The current battery fitted to the vehicle is of a standard 70a/h lead acid type and not the 70a/h AGM type technology, this is incorrect for the specification and configuration setup of the vehicle.

This is what the garage have said.

A copy of the diagnostics they just sent me: http://i63.tinypic.com/29pc5kz.jpg

dale1uk · 30 Jun 2016 at 17:46

Clarkey said:
Fault code this, fault code that. How hard is it to put a damn volt meter across the battery, it's not rocket science to see if the alternator is working.

Is it always as easy as that though? For example the alternator in my mk2 mx5 is regulated by the ECU. So if the ECU isn't telling the alternator to charge the battery it won't, so checking the voltage at the battery with the engine running surely won't give you the full picture of what's going on?

slick rick · 30 Jun 2016 at 17:48

Interesting, I find it strange that you have a genuine Mini branded battery fitted and the garage suggest that it's wrong. Do you know anyone with BMW diagnostic software and cable or Carly for BMW app, as you would be able to see what type of battery you car is currently coded for.

If they are correct that the installed battery is wrong, I wonder if this could give a false indication that the alt is faulty when it may not be? Getting a reading of 14v from it suggests that is functioning properly.

Meatball · 30 Jun 2016 at 18:32

slick rick said:
Interesting, I find it strange that you have a genuine Mini branded battery fitted and the garage suggest that it's wrong. Do you know anyone with BMW diagnostic software and cable or Carly for BMW app, as you would be able to see what type of battery you car is currently coded for.

If they are correct that the installed battery is wrong, I wonder if this could give a false indication that the alt is faulty when it may not be? Getting a reading of 14v from it suggests that is functioning properly.

This is what I'm wondering / hoping! I don't know anyone with BMW diagnostics. I've contacted the MINI garage I bought the car from and they have no records of a battery change. They requested I sent a picture in, which I have, and their master technician will get back to me. If it is the wrong battery it has gone at least 2.5 years with no issues until now.

If I go ahead and just get the battery replaced and it turns out the alternator is actually faulty, will this damage the new battery?

My gut tells me the alternator could be at fault considering the car cut out whilst driving. My understanding is the alternator should keep the car going once started, unless it's faulty!

Meatball · 1 Jul 2016 at 16:02

Just on my way to pick up the car now. I requested they just replace and program a new battery. I requested they leave the alternator so I can seek a cheaper alternative.

If the alternator is actually faulty and on its way out I'm assuming the faults will manifest quite quickly? Should I be driving it straight to the nearest alternator refurb shop?

roadie · 1 Jul 2016 at 16:31

What a mess. Hope you can get it sorted quickly.

slick rick · 1 Jul 2016 at 16:32

If it was my car I would see how it goes with the new battery for a while and if it started giving signs of alternator issues again then get it sorted, as with the prices you were quoted for a replacement it is a lot of money if it isn't actually faulty. This is just my personal view of course.

I might be worth looking up refurbished or replacement alternators though so you know where to get one at reasonable cost in future if needed.

Orionaut · 1 Jul 2016 at 19:59

Meatball said:
Part: 61216924021 - Alternator 150a/h (£560.98)
Part: 12317619254 - Alternator 120a/h (£120.95)

Oh for the days when Alternators were not only £25 a pop! And, yes I know that £25 represented rather more back then.

But, and much more to the point!

I could put three different Alternators in the back of the Van and know I could cover 90% of the vehicles I might encounter.

Nowadays (Now everything is sooo much better!)

Three different units wouldn't cover a single model in a single year!

When and why did the world go insane! :confused:

Heisenberg · 1 Jul 2016 at 20:07

Yeah, not as easy as some are suggesting by sticking a multi meter across the battery with the engine running. Most cars nowadays use smart charging which is regulated by the ecu. The smart arse comment about "this is how they are taught these days, no proper diagnosis" is pretty ignorant to how complex modern cars are.