Another Battery Question

[XMetal]

When did BMW start fitting AGM batteries in the M? RealOEM.com list an AGM for the M roadster and coupe, but I was surprised to see that my '08 M Coupe had a vent tube connected to the battery, which was obviously not an AGM. Anyone have any insights? Does anyone here have the OEM AGM battery in their Z4M? Just curious.

BTW...the OEM AGM battery list for > $400

[ebruder]

My 2007 M, build date Nov.,06 had the AGM battery, which lasted 2 years and was replaced under warranty with another AGM.

EB

[mfanatic325]

My Z4MC has a build month of December 2006, so is a 2007 model. Let me go check the battery real quick...

edit: errr...I could only find on the label "S: 61 21 7 553 952"
When cross-referencing this # on RealOEM, this is what came up: http://realoem.com/bmw/partxref.do?part=61+21+7+553+952
WTF, it says that this part # battery is for E46 non-M's...?!?!



And this is the only Z4M battery link I could find: http://realoem.com/bmw/showparts.do?...12&hg=61&fg=30

How can I tell if it has an Absorbing Glass Mat in it or not : ?

[chickdr]

One is white and the other is black. I believe the AGM battery is white.

[mfanatic325]

I got the black one

[esqu1re]

I have the black one too. A battery is a battery, though.

[esqu1re]

I have the black one too. A battery is a battery to me, though.

[Ron Stygar]

Originally Posted by chickdr

One is white and the other is black. I believe the AGM battery is white.

AGM is black.

[Ron Stygar]

Originally Posted by XMetal

When did BMW start fitting AGM batteries in the M? RealOEM.com list an AGM for the M roadster and coupe, but I was surprised to see that my '08 M Coupe had a vent tube connected to the battery, which was obviously not an AGM. Anyone have any insights? Does anyone here have the OEM AGM battery in their Z4M? Just curious.

BTW...the OEM AGM battery list for > $400

AGM is black.
Has a vent.
61 21 7 553 952 AGM retails for $204.

951 AGM comes with the car. One number less. That's how they know.

http://www.bimmerfest.com/forums/showthread.php?t=50935

[XMetal]

Originally Posted by Ron Stygar

AGM is black.
Has a vent.
61 21 7 553 952 AGM retails for $204.

951 AGM comes with the car. One number less. That's how they know.

http://www.bimmerfest.com/forums/showthread.php?t=50935

I thought AGM are sealed and does not require a vent tube?

[mfanatic325]

Okay so mine adds up technically, because I have the full service record for the car (since I'm the 2nd owner). And it states that the battery was replaced early 2009. So I should have another year left or so, approximately, before it'll need to be replaced =P

[Ron Stygar]

Originally Posted by XMetal

I thought AGM are sealed and does not require a vent tube?

I thought so too.

I think it is for a fail.
I had my vent off for some time and put it back.

[XMetal]

Realoem.com shows the AGM battery for $400 => http://www.realoem.com/bmw/showparts...12&hg=61&fg=30

[Ron Stygar]

Originally Posted by XMetal

Realoem.com shows the AGM battery for $400 => http://www.realoem.com/bmw/showparts...12&hg=61&fg=30

021 one is the one from Euro that they wouldn't send here.
Maybe they do now.

I purchased 61 21 7 553 952 AGM. Retails for $204 now.
I purchased it back then less than a $100. No shipping since it's picked up local. North Haven in CT gives 25% off from retail.
You can order it from any dealer and pick it up local.
It shows that with the link I posted earlier.
Not sure what they are using now.

Can also go to www.eastpenn-deka.com for less.

[XMetal]

Thanks Ron!

I found one of your post over on bimmerfest => http://www.bimmerfest.com/forums/sho...t=50935&page=2. That post showed that you didn't need the vent tube. In the post above, you mentioned that you have re-installed the vent tube. Did the AGM battery that you got had a vent hole? Does AGM battery require venting like lead-acid? Do you know why some AGM have vents and others do not?

[Ron Stygar]

Originally Posted by XMetal

Thanks Ron!

I found one of your post over on bimmerfest => http://www.bimmerfest.com/forums/sho...t=50935&page=2. That post showed that you didn't need the vent tube. In the post above, you mentioned that you have re-installed the vent tube. Did the AGM battery that you got had a vent hole? Does AGM battery require venting like lead-acid? Do you know why some AGM have vents and others do not?

That's the link I posted here.

The two I have, have vents. The Deka one does too.
Like I said, I think that it vents on a fail.

Call Exide or eastpenn-Deka and see what they say.

[Ron Stygar]

Originally Posted by XMetal

Thanks Ron!

Do you know why some AGM have vents and others do not?

AGM batteries are becoming the preferred battery for marine use. They excel because they will typically give you several years of maintenance free service. Unfortunately, most AGM batteries vent at 1-2 PSI causing them to corrode surrounding electronics similar to the Gel batteries. Almost all AGM’s today use recycled lead shortening their service life. They are typically more sensitive to charging than a flooded battery; however they are less sensitive than a gel. There are many AGM’s on the market so don’t just go out and buy an AGM battery and think you have the best. You may have been better off saving that additional money you just spent and bought that 100 year old technology found in a new flooded battery.