PDA

View Full Version : AGM or Lead-Acid Battery?


mostroad
07-30-2012, 12:18 PM
I have a 2008 535xit, and it's time for a new battery. I will register the battery and reprogram for it if necessary, but I need help on deciding whether to replace with battery with a Lead-Acid like the one that's in there, or with an AGM.

Following are the two I'm considering, both from Autozone:

OEM-replacement Lead-Acid 95r size:
http://www.autozone.com/autozone/parts/Duralast-Gold-Battery/_/N-8gcxb?itemIdentifier=820339_0_0_

AGM H8 size:
http://www.autozone.com/autozone/parts/Duralast-Platinum-Battery/_/N-8gcxb?itemIdentifier=319459_0_0_

Thanks for sharing your thoughts and experiences.

NoQuarter
07-30-2012, 01:21 PM
I have a 2008 535xit, and it's time for a new battery. I will register the battery and reprogram for it if necessary, but I need help on deciding whether to replace with battery with a Lead-Acid like the one that's in there, or with an AGM.

Following are the two I'm considering, both from Autozone:

OEM-replacement Lead-Acid 95r size:
http://www.autozone.com/autozone/parts/Duralast-Gold-Battery/_/N-8gcxb?itemIdentifier=820339_0_0_

AGM H8 size:
http://www.autozone.com/autozone/parts/Duralast-Platinum-Battery/_/N-8gcxb?itemIdentifier=319459_0_0_

Thanks for sharing your thoughts and experiences.

Get an AGM for sure. I don't know anything about the one you linked but I got my OEM AGM from the parts counter at the dealer for ~$210.

Mac Hadley
07-30-2012, 01:23 PM
I got an AGM. It is better than the replaced battery.

mostroad
07-30-2012, 02:21 PM
My dealer wants $389 for the battery alone! Penskeparts and BMW of South Atlanta are each asking $269 for the part on their web stores. I'll go the the local dealer and try to talk them down. Thanks for the advice.

http://parts.bmwofsouthatlanta.com/products/Battery-from-Exide-Warranty-Only-AGM-92AH/8402869/61217639053.html

booyaazaa
07-30-2012, 03:30 PM
Get an AGM for sure. I don't know anything about the one you linked but I got my OEM AGM from the parts counter at the dealer for ~$210.

+1

I replaced my e53 factory with a agm and it ran great for 6 years. It was even in it till i traded it in 4 months ago.

jsimon7777
07-31-2012, 08:05 AM
I'd have had to wait a few days to get an AGM so I just went with a normal battery and saved a hundred bucks. It might not last as long, but it will cost less over the lifetime of the car. No problems so far. At some point I'll get around to reprogramming it.

dave154304
07-31-2012, 09:04 AM
To the people who mention re-programming for the new battery... What does it take to do that on your own? I have to replace a battery - and it is killing me to pay the dealership prices for the installation and reprogramming...however, I would like to reprogram the system since that seems to be highly recommended.

Thanks in advance.

HPIA4v2
07-31-2012, 10:30 AM
To the people who mention re-programming for the new battery... What does it take to do that on your own? I have to replace a battery - and it is killing me to pay the dealership prices for the installation and reprogramming...however, I would like to reprogram the system since that seems to be highly recommended.

Thanks in advance.
This has been discussed before, but potentially buried in the posts.
there are "registering" and "programming", two different things. registering is to let the car knows that a new batt of the same type has been put in in place of the old one. new batt requires less charge compare to old one (of the same type).

Programming is needed when you change the type, from regular batt to AGM for example. here the charge profile needs to change since AGM batt requires yet less charge.

Many tools will do registration but not programming. For programming you need GT1 or autologic, which not many weekend tech/mech has.

dave154304
07-31-2012, 06:53 PM
Alright, thanks for the clarification. I'm a newbie at this car stuff...anybody have a source for software and cabling to do the battery registration and basic diagnostic troubleshooting? Again, thanks in advance.

mostroad
07-31-2012, 08:27 PM
There's a good DIY to battery programming and registering here:

http://www.e90post.com/forums/attachment.php?attachmentid=647190&d=1329707988

from this thread:

http://www.e90post.com/forums/showthread.php?t=532315&page=3

racooper3
07-31-2012, 08:32 PM
I bought the Autozone AGM-H8 battery for $160 and it is identical to the BMW AGM battery. I converted from Pb acid battery to the AGM style, which requires the reprogramming.