AGM battery in BMW E46 or not? (OE was not AGM)

[slo town]

OP:

I am the original owner of a 2003 BMW E46 330Ci ZSP. I do 100% of all maintenance, modifications, and repairs myself. Since taking possession of the vehicle, it has not once had anyone else work on it.

1) The battery does not need to be registered in your car.
2) I've had an AGM battery in my E46 for 3 or 4 years now (a group 49 or 94, I forget now).
3) My E46 is only driven about 1,500 miles per year and I have never had battery discharge issues with the AGM.
4) Be 100% CERTAIN TO PROPERLY VENT THE BATTERY WHEN YOU INSTALL IT! The top of the battery will have two small vent plugs. You will use only one of those. Make sure the unused vent hole is plugged.

Questions? PM me.

Scott

 

[97tbird]

Just ordered the battery *AGM H7* at AAP and saved $50 with an online coupon.

Called them and told them to make sure that it is fully charged before I come to pick it up / get it installed in about 5 hrs.

Now, I will try to jump start the car using the booster pack/jump starter when I am ready to lave .


*** I am reading a lot of stuff about how jump starting the car can damage the alternator and ECUs and whatnot, but checking on bimmer forums, people seem to do it all the time without any problems.
--I will only be driving about 10 min to AAP if I get it started.
--Last night when I checked the voltage (without car running, of course) using the in-dash OBC "test" mode, it showed 8 volts.
--Is it risky to jump such a low battery as far as the alternator is concerned?

Any thoughts on tthat before I try it?

Thanks again for the comments.

 

[97tbird]

Thanks! Just PM'd you

Originally Posted By: SLO_Town
OP:

I am the original owner of a 2003 BMW E46 330Ci ZSP. I do 100% of all maintenance, modifications, and repairs myself. Since taking possession of the vehicle, it has not once had anyone else work on it.

1) The battery does not need to be registered in your car.
2) I've had an AGM battery in my E46 for 3 or 4 years now (a group 49 or 94, I forget now).
3) My E46 is only driven about 1,500 miles per year and I have never had battery discharge issues with the AGM.
4) Be 100% CERTAIN TO PROPERLY VENT THE BATTERY WHEN YOU INSTALL IT! The top of the battery will have two small vent plugs. You will use only one of those. Make sure the unused vent hole is plugged.

Questions? PM me.

Scott

 

[Pelican]

Originally Posted By: 97tbird
Car is a 2005 BMW E46. Factory/regular battery is a traditional (not AGM) battery.
I've read about some advantages of AGM batteries.
Advance Auto and Autozone both have AGM (and traditional) batteries for my car (H7 size).
Are there any disadvantages or problems in using an AGM battery in a car that didn't use an AGM battery from the factory?
Are there any special maintenance requirements when using an AGM battery?
**BTW Both AZ and AA have disclaimers when searching for batteries for my car: IDK if they'll refuse to install this:
"REQUIRES PROFESSIONAL INSTALLATION; Battery is vented to outside; Computer must be reset; See manual for safe installation; 30 minute Install; Battery in trunk; DO NOT attempt to install batteries in this vehicle. The battery information must be reset in the power management system.; Please inform customers and recommend that they have their battery replaced at an authorized BMW dealership/shop."
I am pretty sure "The computer must be reset / battery information must be reset in the power management system" part is non-sense, as no such procedure is needed in an E46 (I've had regular batteries installed before at Walmart but not at AA or AZ). I think all that resetting/reprogramming stuff is only for E90 gen and later.


You'll be just fine with an AGM and you'll have to go through the usual procedure when changing batteries.
The AGM will be better than the standard in as much as it can handle all the electronic load much better.
The ONLY difference is that it will perform at peak efficiency till the end, it will die without any warnings, contrary to the standard battery which will give you signs. IMO Odissey is the best, but very pricey, any brand name AGM battery will do IMO.

 

[97tbird]

UPDATE: forgot I had a Noco Genius G3500 charger

and hooked it up to engine bay terminals for 5 hrs, and battery voltage went up to 12.1 on the in-dash display and just started the car and it's now idling. (Jumping was not needed)
With the car running the voltage goes up to 14.1 volts so I guess that means alternator / charging system is ok.
Now going to AAP and get battery tested and replaced.

Will update again when I am back.

 

[Quattro Pete]

I thought your car was supposed to have an H8 battery, no? I guess H7 will work,too, just slightly lower CCA.

Originally Posted By: 97tbird
Price difference is about $20 more for the AGM vs regular.

Regular EverStart Maxx H8 is $122 at WM, so you're paying quite a bit more for AGM, even when you factor in that $50 coupon.

But functionally, there will not be any problem running an AGM battery in yours. For a car that's not driven regularly, the most important thing to do, regardless of battery chemistry, is to put it on a battery maintainer.

 

[97tbird]

The correct size is 94R (H7) for this model AFAIK. That's what comes up in all battery finder sites. But I know people use many other battery types (49DL, etc - so that might translate to an H8 perhaps)

The AGM H7 (850 CCA) I got exceeds the BMW OE (Bosch?) battery CCA spcecs (750 CCA).

So UPDATE:

Went to AAP and had the old battery tested and it registered 451 CCA (rated 790 CCA). (tested "bad")
The old battery was MUCH older than I thought. It was 5.5 yrs old and for some reason I was thinking more like 3 yrs old.
It was an Everstart Maxx with 790 CCA.

--Got the Autocraft AGM H7, CCA 850 A, CA: 1000 A, 80 AH, 3 yr warranty.
--Put it in and the in-dash OBC went to 12.5v and then to 14.2 with engine running.
--The guy at AAP was really nice, did it quickly (didn't even lose any presets) and I made sure the extra vent hole was plugged and the normal vent hold is connected well to the vent tube.
--(He said they don't refuse to install batteries in BMWs as long as the customer has provided easy access to battery by removing all the carpeting and panels that cover the battery compartment in trunk)
-- PETE: I did ask about the battery maintainer (I think my Noco Genius G3500 can do that?) and he said it's a good idea but NOT to do it "right off the bat" but do it after the battery has been used for a while... (???)

So, all in all, the factory OE battery lasted about 6.5 yrs, the Walmart (Everstart Maxx lasted 5.5 yrs... We shall see how the Autocraft AGM does.)

 

[Quattro Pete]

Originally Posted By: 97tbird
The correct size is 94R (H7) for this model AFAIK. That's what comes up in all battery finder sites. But I know people use many other battery types (49DL, etc - so that might translate to an H8 perhaps)

OK, cool. Reading through various BMW forums, it seemed like a lot of people were using H8 in their E46s, so I wasn't sure which one was correct.

Quote:
-- PETE: I did ask about the battery maintainer (I think my Noco Genius G3500 can do that?) and he said it's a good idea but NOT to do it "right off the bat" but do it after the battery has been used for a while... (???)

Check this thread regarding Noco:
https://bobistheoilguy.com/forums/ubbthr...un_#Post4510508

 

[97tbird]

I just checked: 49DL, which some people use in $46, is an H8. So I guess either one works, and both exceed CCA of the OE battery.

re: Noco: Thanks! Interesting about the Noco G3500. I Guess now that I have an AGM, if I use the Noco G3500 to "maintain", I'd select the "Cold/AGM" mode. I wonder if it will do the same bizarre thing you experienced in AGM mode, or is it a flaw only on the "regular" 12v mode... ?

IF I do decide to use the Noco to maintain/charge after letting the car sit for a while, I am going to check the voltage of the battery using the in-dash display, to see what it shows after the green LED turns solid
... It shouldn't be (need to be) more than 12.5 V or so, correct? (That's what it showed when the AGM was put in, withOUT running the engine).
If it shows more than that I think I'd also not use it to maintain without monitoring the voltage.

 

[CharlieBauer]

AGM mode on most battery chargers isn't the right mode for the non high end AGM batteries.

Reading voltage on a battery when it is installed is never going to be reliable unless you know which circuits are still drawing power when you take the reading and you have removed the surface charge.

 

[Quattro Pete]

Originally Posted By: 97tbird
IF I do decide to use the Noco to maintain/charge after letting the car sit for a while, I am going to check the voltage of the battery using the in-dash display, to see what it shows after the green LED turns solid
... It shouldn't be (need to be) more than 12.5 V or so, correct? (That's what it showed when the AGM was put in, withOUT running the engine).
If it shows more than that I think I'd also not use it to maintain without monitoring the voltage.

Checking voltage through the in-dash display can be misleading, since at this point all of the car's electronics are powered, so the battery is under load. Easier to just use a DMM at the battery with all systems off, I think.

 

[CharlieBauer]

AGM mode on most battery chargers isn't the right mode for the non high end AGM batteries.

Reading voltage on a battery when it is installed is never going to be reliable unless you know which circuits are still drawing power when you take the reading and you have removed the surface charge.

 

[97tbird]

Originally Posted By: Quattro Pete
Easier to just use a DMM at the battery with all systems off, I think.

Thanks! I've wanted to buy one for a while but never got around to it. Any recc's for a decent but not too $$$ DMM?
Also: Can I use the engine bay +/- terminals for this?

 

[Quattro Pete]

Originally Posted By: 97tbird
Originally Posted By: Quattro Pete
Easier to just use a DMM at the battery with all systems off, I think.

Thanks! I've wanted to buy one for a while but never got around to it. Any recc's for a decent but not too $$$ DMM?

Depends on what you are going to be measuring. If just low voltage such as household or car batteries, then anything will do, even the free HarborFreight one.

I got an Etekcity MSR-U1000 for around $30 from Amazon some time back and have been happy with it. I also have a clamp meter (Uni-T UT210E) that has all the basic DMM functions plus current reading (both AC and DC) via clamp.

See these two threads:

https://bobistheoilguy.com/forums/ubbthr...ati#Post4369157

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4289495/1

Quote:
Also: Can I use the engine bay +/- terminals for this?

Possibly. Not sure how much voltage drop there is along the way though.

Is your battery hard to get to? Mine is right there in the trunk - it takes literally 1 second to get to it.

 

[97tbird]

Thanks for the links, Pete.

No, the battery in the trunk is not that hard to get to, just have to remove one panel, but then the posts already have terminals/cables around them, etc. I just thought the engine bay terminals are free of clutter and really easy to connect to.

 

[jeepman3071]

Originally Posted By: rooflessVW
Originally Posted By: JHZR2
You sure about registration?

Yes, I'm sure. Registration came about in the 3er with the E90 chassis.


+1

E90's started with the battery registration. E46 and prior don't have it. My friend tried looking for an Odyssey battery for his 2005 E46 but it was hard locating the correct size since almost nobody sells that brand around here. He ended up going with an Everstart from Walmart and it has been fine for over 4 years.

 

[Alfred_B]

I would stick with the OEM recommendation. AGM have better performance characteristics but have different engineering as well that your car is not designed for. My BMW is similar vintage and hasn't had any issues with wet cell battery in the trunk. It's an Autozone Duralast Gold that's now 9 years old.

My Audi recommends AGM and the OEM Varta lasted 8 years. The replacement is again from Autozone that I hope will last as long.

 

[SHOZ]

I ran AGM Odysseys in a Taurus, Gen Coupe and John Deere with no problems. John Deere has been in use since 13 years with no issues. Don't even need to boost it in the spring after sitting a winter.