twobeemers

Thought I'd share my battery replacement experience from this past weekend so it made it to the archives for the next guy.

I had had a few instances of getting in the car Monday mornings after the car had sat all weekend and getting an error that said the battery had been disconnected and I had to reset the time and date. The car still started and ran fine, but I made sure I had jumper cables in the car non the less. The only other sporadic symptom was the iDrive knobby would get a little weird sometimes after starting and spin on it's own. The battery was original to the car, a 2007 550i.

Last week I drove the car to work one morning and accidently left the parking lights on when I went into work. When I came out for lunch, that minor drain was just enough to keep the car from starting.

I got a jump (follow the directions in the manual!!!) and got home fine, and for the next couple of days I kept close tabs on battery voltage and how the car was starting. And I turned everything off BEFORE shutting off the car (probably overkill, but I knew I was on the edge). For the record, I was getting voltages anywhere from 11.9 on down to 11.4. The "state" fish eye on the battery was black.

After looking around both here and other places I settled on one of two batteries - a Napa Gold 75 for $106 or a EverStart Maxx-49 for $82 from Wal-mart (I know - I hate going in there, too). I settled on the EverStart for the price, the 3 year free replacement warranty, the recommendations from here and other sites, and the fact that they had one when I was available to go get it.

I installed it myself. I hooked up my battery tender to the pins under the hood and moved to the truck to replace the battery. I won't go over removal and installation here - it's covered in numerous other places and it's quite straightofrward. One thing you'll notice is that the EverStart is slightly shorter in length than the factory battery. Someone had their thinking cap on when they engineered our cars because there are three different positions for the battery clamp to screw into on the bottom of the battery compartment - those crazy Germans. One such threaded hole seemed to be positioned with this battery in mind and it went right in. Dimensionally, the EverStart is otherwise an exact fit.

The stock battery vents from the positive terminal end and has a right angle connector, a very short hose, and then another right angle connector into the chasis. The EverStart battery vents from the center of the battery on the terminal side. The battery came with a vent hose and a straight connector. The hose was several inches in length, but several inches too short to connect in any way to the other hose. I ended up having to swap out the car's very short vent hose with a longer piece of plastic tubing I had laying around. Note - make sure the run is downhill the whole way to prevent icky stuff (tech term) from building up in the tube.

I think that's about it. Terminals were clean as a whistle. The batter compartment had a very small bit of corrosion in it which I cleaned out. I also took the oppoortunity to slather the painted surfaces with a bit of wax. <shrug> Hey, can't hurt.

Hardest part of the project? Removing the battery from the battery compartment. Seriously! The connectors BMW uses are amazingly easy to get to and operate, and the positive terminal connection is minor engineering miracle. Oh yeah - there is a single, very small wire that runs from the positve side of the battery connector to the negative side and it's not tied down to anything. I think I could have easily messed up that wire removing the battery if I had just horsed it instead of noticing it and moving it along the way.

I have the AutoEnginuity scan tool which has a function to "code the battery" to the car (basically tell the computer that the battery is new and charge it accordingly. I've had the AE tool for several years and having it to perform this function alone paid for itself - something to think about.

There you go! Good luck with your battery adventure.

turboawd

doesnt the walmart battery have less cold cranking amps?

time will tell if the battery registration is worth it.

AchtungE60

You got a EverStart Maxx-94R not 49. And it is a bit shorter but has more CCA than the OEM BMW battery. Been using them for years and years over OEM. They're made by Johnson Controls.

south87

no the op did get the 49 it sounds like.. because the 49 vents from the middle. although it seems like some specs can vary by year/region.. typically the 94 has 765cca while the bigger 49 has 850cca. the main advantage to the lower cca 94 is that is vents from the side so you don't have to figure out a vent extension like the op did. this is why i went with the 94. it just plugs right in. also bear in mind that there are THREE stock size batteries for this car.. so saying that a particular battery is bigger or smaller or has more or less cca than stock depends on which stock battery you had to begin with. also remember that cca is only one measurement.. and that a battery's 'reserve' or amp hour rating could be more important. the everstarts don't list these measurements. yeah, i've been doing a lot of homework batteries lately

fburkart

a helpful forum. thanks. I had to have my SA run an energy diagnostic today (after all the clocks, mileage and power steering were not operating properly and after the car was struggling to turn over). Turns out my 06 550i's battery has run its course. BMW of course wants $600 to replace it with an OE battery that is registered, etc. My independent service guy says that's baloney and wants to charge $200 for his aftermarket battery (installed). He also says registration is unimportant. Can anyone shed light on this? Thanks.

south87

$600 for a battery.. that has to be a new world record. i am not an expert, but i think for what it costs to have a battery registered, i'll take my chances skipping it. as i mentioned above, i put a walmart everstart maxx 94r into my 06 525i. no registration. a month later, no problems. to be fair, most people say that the issue is not that the battery will go bad in a week, but that its long term lengevity will be compromised. but i'll take my chances. if the walmart battery goes bad in 3 years or less, you get a new one for free anyway. however if i were you with the v8 engine, i'd go with the everstart maxx 49 model which is 850cca vs the everstart 94r's 765cca. the only issue you'll have is that the vent on the 49 is in the middle.. so you'll just need to extend the vent tube. no big deal $77 vs. $600. let me know if you have any questions

fburkart

Thanks for the thoughts.

Curmudgeon

+1. Replaced mine with the Wal-mart 94r nine months ago. No problems. Did not register. Monitored battery doing fine. Car starts in a New York minute and its a V8. Don't drive that much so maybe battery needs more aggressive charging. Here is why I went with Wal-mart, all 94r except stealer:

AutoZone = $164
Batteries Plus = Fugettaboudit. Ray-o-vac with only two yr. warranty. $124
Stealer = $234 for an OEM
Interstate = $134
Wal-mart = $66

Replacing the battery every two or three years is still cheaper.

twobeemers

Nope, got the 49. And yes, it's made by Johnson Controls.

So far, so good.