Battery Question

[rba]

I have a 2009 3.0i and I am replacing the battery. There is some confusion on if the battery in the car is a lead acid or AGM. The case is white...and I have been told that there was a mix of lead acid and AGM batteries put in this car in this time period. I checked Real OEM and it indicates AGM...but I am not so sure. Any input would be helpful...I don't want to have to recode the car if I can put the same battery type back in...and yes I know it needs to be registered...I can register at the moment but cant code.

Thanks for the help.

[ZetaTre]

My understanding is that batteries with a white casing are wet cell, while the AGM are black casing. Also wet cells have a vent while AGM do not have a vent. If you shake a wet cell you can hear the liquid sulfuric acid splashing around, while the AGM is totally silent (alternatively you can flash a light behind the casing and move it so you can see the shadow of the liquid moving around). If there's liquid, it is not AGM.

I have a 2009 35d (production 07-2009) and it had a wet cell white case battery with a vent. I just recently had to replaced it, and just like you, I could register the battery, but couldn't code and AGM (nor wanted to pay someone to do it) so I decided to replace it with the wet cell Interstate battery recommended here: http://www.xoutpost.com/bmw-sav-foru...ement-diy.html

BMW dealer network doesn't sell white case wet cell batteries anymore.

[ChuckG]

The AGM battery in my X5 is white.

[ZetaTre]

Originally Posted by ChuckG

The AGM battery in my X5 is white.

That's interesting!!! How are you able to tell is an AGM? My prior battery was also white and I assumed it was wet cell.

[rba]

Hummm.....seems like there is still no firm confirmation on the issue. I guess I will go home and see if I can tell if there is liquid in the battery to confirm if it is non AGM or not. This...in my case will be somewhat of a challenge.....trying to swing around a 100lb dead weight and hear for liquid.

Anyway...if there are any more thoughts, p[lease post. I appreciate the comments.

[ZetaTre]

I just remembered something else now.

At one point soon after I bought the car, I did some coding with NCSExpert. In that occasion I dumped the FSW_PSW file for all the modules and kept a backup of the original stuff.

As I was doing research on how to code the AGM battery, I remember taking a look at the FSW_PSW for the CAS (the or one of the module where the type of battery is registered) and I confirmed that my car had a wet cell battery registered (90Ah, if I recall correctly).

The line in the CAS FSW_PSW file is called KLASSE_BATTERIE and among the acceptable parameters there's a set where the Ah rating is followed by "_AGM" signaling it is a dry cell battery.

I never ended up doing it because I couldn't come to a definite conclusion on whether or not you just change the VO, the CAS FSW_PSW, both or something else... So I read people were fine with the regular wet cell batteries and put it to rest...

[motordavid]

Here is a snippet from the Web, and maybe not the final declarative method to 'tell', but worth a look at your existing batt label:


Read the battery label. Liquid--or flooded--lead acid batteries will say "lead acid," "wet cell," "flooded lead acid" or "liquid lead acid" on the label. Gel-filled lead acid batteries will say "Gel-Filled" on the label. AGM lead acid batteries will say "AGM" or "Absorbed Glass Mat," "sealed regulated valve," "dry cell," "non-spillable," or "valve regulated" on the label.

Look at the top of the battery. Liquid lead acid batteries have caps or removable tops unless they say "sealed" on the label. Gel-filled and AGM lead acid batteries have flat tops except for the positive and negative terminals.

Read the battery label. Liquid--or flooded--lead acid batteries will say "lead acid," "wet cell," "flooded lead acid" or "liquid lead acid" on the label. Gel-filled lead acid batteries will say "Gel-Filled" on the label. AGM lead acid batteries will say "AGM" or "Absorbed Glass Mat," "sealed regulated valve," "dry cell," "non-spill able," or "valve regulated" on the label.

Look at the top of the battery. Liquid lead acid batteries have caps or removable tops unless they say "sealed" on the label. Gel-filled and AGM lead acid batteries have flat tops except for the positive and negative terminals.

Read more : How to Tell the Difference in Gel, AGM or Standard Batteries | eHow

I have never had to deduce whether a current batt was wet cell or AGM, as I have always replaced wet cell, or whatever it was, with an AGM, problem free. But all in cars/m'cycles that didn't need 'registering',
GL, mD

[ard]

^There ya go...showin' off with your superior google skillz...

[mart_dev]

Or you could just phone up BMW and quote the number on the battery to them. I did this and they were able to confirm that I have a wet cell battery. I was also informed (perhaps incorrectly) that white case batteries which bear the BMW logo are wet cell and all have a vent tube on one side while the AGM batteries do not.

[rba]

Great information from everyone...thanks. I have confirmed that the "White" case batteries are lead acid and "Black" case batteries are AGM.....that is for BMW OEM batteries. So now I know I have a lead acid battery.

Thanks everyone.