Z4M Battery Question

[MyMRoadster]

Well, I have done it again. My 2006 M Roadster sat too long and the battery is dead. I bought a Battery Tender last night and put it on the charge to see if it would recover --- it did not. Not even enough to turn it over.

This is the 2nd time I have done this. The first time it was my fault and BMW covered the battery under warranty after an appropriate scolding. They warned me about keeping it conditioned and I did not heed the warning.

So, I don't want to take it in to the dealer and ask them to replace it under warranty when it was my fault (again). However, I also don't want to pay BMW to put an OEM battery in the car.

The problem is that I have done quite a bit of searching online and both Autozone and O'Reily do not seem to have a replacement battery. This can't be true, but it didn't match anything to the year/make/model. Furthermore, PelicanParts.com doesn't even have the Z4M listed.

Does anybody have the BMW part number for this battery? How about the specifications? Any recommendations for a replacement would be great as well.

Thanks ... Dave

 

[WLH]

I seem to remember reading somewhere that the battery requires a vent tube connection and that makes it really difficult to fine this side of a BMW dealer.

 

[sammyz]

Out of interest, how long was the car left standing for the battery to be dead. I've left mine in the garage for two weeks or so without turning it over and it's never been a problem even in Winter.

 

[Wondermike]

Part number is the same as loads of other BMWs 61 21 6 924 021

 

[MyMRoadster]

Thans and thanks! It was about two weeks ... Maybe a little longer.

 

[MyMRoadster]

Holy crap ... It's over $400 @ Pelicanparts.com

61-21-6-924-021-BOE
Genuine BMW Part: BMW OEM Part
   - This is a special-order, non-returnable, BMW part
      (availability and shipping charges may vary).     [More Info]

$413.75

 

[WLH]

I think my dealer sells the battery for $379.00...

 

[Mikey]

Bloody hell! How come your battery is dead after two weeks? It should`nt go dead after such a short period. I`ve had mine stood for two months at a time before and ok it would take a couple of turns but would always start. Something must be discharging your battery.

 

[MyMRoadster]

Well, good news. The >$400 price tag of a new battery gave me more incentive to work on recovering the dead one. I'm leery about jumping a car with all of the electronics in them today --- but I did it anyway and it fired as expected. I took it out and drove it for 16 miles between 3 & 4k RPM. It ran fine. The big test was when I got it back home and turned it off and tried to restart it on the battery. It fired!

I put it on my Battery Tender and crossing my fingers that it recovers the rest of the way. The Battery Tender has a feature that shows a failed battery (sulfation) and it is not signaling as such. I might have got out of this one cheap.

Thanks all for your help.