A weird one today…

London_Paris

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152
As the weather is beautiful in France today a drive was in order. The goal was the foret de troncais, which the michelin guide vert gives 3 stars, and is 90km from the house.

About an hour from home, I went into a parking lot of a supermarket but realized I needed to go down the road another 100 meters and go in a different entrace. So quick u-turn, and while waiting to turn back on the main road I get the warning chime and a low oil pressure warning message. A quick look at the rev counter confirms the car has just stalled for no obvious reason. Cycle the key off then on and she starts perfectly, no warning lights, no messages. I clear the intersection, go across to another parking lot to stop and check the oil level, and it was dead center of the dipstick as it should be.

The car had a major 4 year service in July at the MD in Paris, and has never stranded me in the 11 years I have owned her.

She is a 4.2 with the 6 speed ZF transmission. When she stalled she was in ”Manual” with 1st gear indicated.

We drove 120km after the stall with no issue whatsoever.

Could an issue with the key cause the problem (immobilizer) or should I just chalk this up to the italian gremlins (The battery takes and holds charge without any problem).

Bill
 

London_Paris

Member
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152
After looking through the service invoices it appears at april 2016 was the last battery change. Purchased a Varta Blue as per the specs in my manual (100 Ah, 850 CCA). Was a bit surprised (probably shouldn’t have been) to see this when I pulled the old battery…

91307

I had no idea they were using AGM batteries as OEM replacement. My 2010 doesn’t do stop/start.

Rgds,

Bill
 

Zep

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9,278
That is very interesting, so the factory have decided that they can spec an AGM battery for everything, whether it has stop/start or not.

According to the parts list this will fit everything after a 4200 / Coupe.
 

Oneball

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11,118
My M3 convertible (not stop/start) came with an AGM as standard BMWs reasoning was the extra drain from the hood mechanism which often used without the engine running.
 
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RoaryRati

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1,626
My 02 spyder also occasionally does that - it's not the battery but I can't remember what causes it - maybe the POT - whatever that is (SI sorts it and it has happened to others)
 

Scaf

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6,577
My XJ has two batteries, guessing one for starting and one for aux power.
My mother in laws B Class Merc also has a small 2nd battery behind a panel in the rear boot, found it when looking for the Jack.
 

Gazcw

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7,763
My XJ has two batteries, guessing one for starting and one for aux power.
My mother in laws B Class Merc also has a small 2nd battery behind a panel in the rear boot, found it when looking for the Jack.
The small one is the stop start battery I believe. Got one in mine that had to be replaced under warranty as ss was not working.
 

2b1ask1

Special case
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20,271
That is very interesting, so the factory have decided that they can spec an AGM battery for everything, whether it has stop/start or not.

According to the parts list this will fit everything after a 4200 / Coupe.
I put a stop start spec Bosch in mine last month, no problem except the extra £60 but wow it cranks quickly now!
 

CatmanV2

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48,786
Two batteries? That's just being posh

Over complex for sure. One battery is the 'house' battery which runs 'all the electronics' The other is the starter battery which is pretty much what it says on the tin.

Over complex charging system and pyrotechnic (!) disconnection.

On the plus side you should never be in a state where you can't start the car. Although that's not exactly true either.

C
 

Tallman

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1,834
Maserati dealer installed an AGM in my QP last year, so it seems to be an official policy…I still use a trickle charger if I don’t drive for more than a week and looking at the charge level it does seem to need it.
 

Gazcw

Member
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7,763
Interesting, I would have guessed the other way round.:eek:
Yeah.. I assume once depleted obviously no more start/stop until charged, but car still has lots of cranking power in main battery for cold starts and general running.