Changing my x3 battery

I am the original owner of a 2006 x3 that now has only 20k miles on it. I have had no real problems with it until now. Given I don't drive it much the battery has gone dead. When I called the dealership they wanted over $700 to replace it. That seems rather steep just to change the battery. They told me only BMW Could synk the battery with the computer. If I had someone else do it they would blow the cars computer. Sounded a bit like cr*p to me. I understand that I don't want to loose all my codes but could I have a charger hooked up to the cables under the hood or use the inside lighter to keep the codes powded while I change the battery? I guess big picture question is if I don't think I can do it can I have someone other then BMW do it for me at a reasonable price without blowing the computer?

Yes, keeping 12 volts or so on the cables while changing the battery is the preferred way to do it, and the computer will never notice a thing. I just attach the two cables from a small battery tender charger onto the positive and negative cables right at the battery. Then I loosen the cables from the battery, pull the old battery out, put the new one in, and re-attach the cables. Piece of cake - done in 60 seconds. If you are concerned about the positive cable getting grounded accidentally while moving the batteries, put a towel between it and the car. I've even done this at a friends house in a pinch with a 9v radio battery and two cheap alligator clip leads from Radio Shack - it doesn't take much to keep the computer dumb and happy.

I've done this on my M5, an X3, two MBs, and a 996, no problem.

BTW, as much as I prefer not to buy parts at the dealership, the batteries that BMW stocks are really good. I went to the dealer with an expired BMWCCA card and they gave me about 20% off, which was $40. I think the same reprobates who own the dealership in RIC own my local one as well.

As it happens, I just had to get a new battery for my 2005 X3 last week. Never used a battery tender, didn't even attempt to keep power to the vehicle during the change. No issues. At all.

BTW - a perfectly good battery anywhere other than the dealer is going to run you about $160-170.

Originally Posted by KaseyRayne

They told me only BMW Could synk the battery with the computer. If I had someone else do it they would blow the cars computer. Sounded a bit like cr*p to me.

Either they misheard what year BMW you had, or they really are a dealer to be avoided at all costs.

No syncing involved at all with your 2006 X3 when the battery is removed and replaced.

As for blowing computers - they must believe that non-BMW techs. are so incompetent they always reverse the polarity when changing a battery.

If you want to keep it easy, just do it without any temporary power connection, and then simply reset the time, saved radio stations, and maybe windows and roof anti-trap mechanisms.

The only thing I "lost" when I changed batteries was the time. Seat memory, radio, windows, everything else was just fine.

I am constantly disconnecting my battery while I work on the electronics I have installed in my 08 X3. The only thing that happens is the seat belt warning light will stay on a bit. It disappears after approx 30 minutes.

BTW, have some fun. Ask them to put that in writing and then call BMWNA customer service and report them.

That is clearly unethical at the least and corporate should know how they are representing them.

They are misleading you or incredibly confused. You can use a charger to keep power to the car but it really doesn't matter. It's no big deal to leave the car without a battery while changing it or whenever you need to.

Originally Posted by dbflight

They are misleading you or incredibly confused. You can use a charger to keep power to the car but it really doesn't matter. It's no big deal to leave the car without a battery while changing it or whenever you need to.

I thought I read on the 3 series forum that the E90's (06-pres) need the dealer to replace the battery's because it has to be re-programmed. Perhaps the 07-10 X3's the are the same?

Originally Posted by codog2

I thought I read on the 3 series forum that the E90's (06-pres) need the dealer to replace the battery's because it has to be re-programmed. Perhaps the 07-10 X3's the are the same?

Some older cars need the radio to be verified with a code, but now the radio can read the VIN directly off some car computer, so that's not necessary. I think maybe the 5 and 7 series have some deal where the car tracks the battery life or something, but I don't think it's important at all.

As for the X3, I've unplugged mine from the battery several times for various reasons and never had a problem.

The whole "re-programming thing" thing from dealers sounds like nonsense.

I accidentally drained my battery during the cooling job. After jump-starting, I found that I had lost the clock settings and got the 4x4 warning light. Everything else was still there and the warning light disappeared in a couple of minutes.

Originally Posted by codog2

I thought I read on the 3 series forum that the E90's (06-pres) need the dealer to replace the battery's because it has to be re-programmed. Perhaps the 07-10 X3's the are the same?

I just read in a recent issue of Roundel that on the e90's only the BMW dealer can replace your battery. Typically charges 500 dollars I think. Another reason to keep the e46.

you need to register the new battery whenever you replace it on newer BMW'S. The computer needs to know if the battery is new that way it will not overcharge it which sometimes causes battery to explode. If you don't register, the new battery the computer will charge it like it's still the old battery and that will cause overcharging. On the X3's ('04-2010) I don't think we have to register the battery same with the e46's.

Wow. Only a dealer can replace the battery?? Me thinks we have drank too much of the "BMW" Kool-Aid.
Volts is Volts, and Amps are Amps. Who's in your wallet?

Originally Posted by Thirdy

you need to register the new battery whenever you replace it on newer BMW'S. The computer needs to know if the battery is new that way it will not overcharge it which sometimes causes battery to explode. If you don't register, the new battery the computer will charge it like it's still the old battery and that will cause overcharging. On the X3's ('04-2010) I don't think we have to register the battery same with the e46's.

That makes no sense whatsoever. Overcharge it and not know? A simple voltage regulator would handle that.

IF it does do that then chalk it up to some more dumb ass engineering. No other way to call it. That type of circuit is what a 10 year geek cuts his teeth on. Real simple stuff.

BTW not insulting you or your knowledge. Just calling BMW DA if they did do that.

Originally Posted by Evlengr

That makes no sense whatsoever. Overcharge it and not know? A simple voltage regulator would handle that.

IF it does do that then chalk it up to some more dumb ass engineering. No other way to call it. That type of circuit is what a 10 year geek cuts his teeth on. Real simple stuff.

BTW not insulting you or your knowledge. Just calling BMW DA if they did do that.

Well, here's a cynical spin on that: maybe that explanation (overcharging) was just dreamed up by some marketing 'genius' to get most people to drop $500+ on a battery change at the dealer instead of taking it to their local Wal*Mart? I mean, your average car buyer won't know enough about these kinds of things to call BS on it...

In the end, there may very well be a good technical reason that requires the newer BMW's to have their battery replaced by the dealer; but I agree with "Evlengr:" it's almost certainly not to prevent overcharging.

We can replace our battery with everstart from walmart or duralast from aurozone with no problem. The ones needed registration are newer e90's, e60's & other models. I can even do battery registration using my INPA or DIS diagnostic software. It won't even take me 2 minutes. And software is free, you only have to buy the cable from ebay.

Originally Posted by Thirdy

We can replace our battery with everstart from walmart or duralast from aurozone with no problem. The ones needed registration are newer e90's, e60's & other models. I can even do battery registration using my INPA diagnostic software. It won't even take me 2 minutes. And software is free, you only have to buy the cable from ebay.

Somewhat rhetorically (as it applies to late-model BMW's): if this is all it takes to register the battery, what's the ultimate purpose for doing it, and why (aside from "because it can") does it cost $500+ at a BMW dealer...?

It's more on premature failure of the new battery and the right voltages to the power modules. But try to go through this thread (i only read some not the whole thread)

http://www.e90post.com/forums/showth...light=exploded

Originally Posted by Thirdy

It's more on premature failure of the new battery and the right voltages to the power modules. But try to go through this thread (i only read some not the whole thread)

http://www.e90post.com/forums/showth...light=exploded

I dunno. There's a lot of speculation throughout that thread, and I'm not an electrical engineer so I can't confidently connect all the dots. But this post seemed to have someone who was speaking out of knowledge, so perhaps I can speculate a bit myself based on his input:

Another post that caught my attention stated that the E90's can apparently have different battery ratings, depending on the options installed (and therefore, the resultant electrical draw). Could "registration" be nothing more than "telling" the charging system which battery rating it's dealing with...? And if you put in an incorrectly-rated battery without "re-registering," it could lead to charging issues: under-voltages; over-charging (based on the battery's perceived rating, not just voltage being monitored by a regulator); battery life issues (decreased life due to undercharging); catastrophic battery failure (as experienced by the OP of that forum's thread)...? But why can't the system just perform a battery diagnostic check itself after a power interruption, whether from a simple disconnect/re-connect or a full battery replacement...? Why the necessity for a dealer-only "registration" process...?

Still, if any of that is true, it seems to me like BMW has over-thought the problem. But I guess that wouldn't be the first time...

d/p

Originally Posted by Thirdy

you need to register the new battery whenever you replace it on newer BMW'S. The computer needs to know if the battery is new that way it will not overcharge it which sometimes causes battery to explode. If you don't register, the new battery the computer will charge it like it's still the old battery and that will cause overcharging. On the X3's ('04-2010) I don't think we have to register the battery same with the e46's.

You probably missed this part of my posting.

realOEM does not show the 2007 X3's battery requiring registration by the dealer. RealOEM shows this caution in the battery section for the e9X's.

I can tell you that I replaced the OEM battery in my '04 X3. Hooked up a jumper battery to the engine terminals to keep the electronics alive and then swapped out the battery (making sure that the + cable did not contact anything).

Originally Posted by Thirdy

you need to register the new battery whenever you replace it on newer BMW'S. The computer needs to know if the battery is new that way it will not overcharge it which sometimes causes battery to explode. If you don't register, the new battery the computer will charge it like it's still the old battery and that will cause overcharging.

Our X3 years don't need registration. New 2011s, yes. 2010 and older X3, no.

One of the "good" things about our X3s having older technology I guess!

Same is true for my Z4, which I just replaced.

My wife's 530xi, however, needs battery registration at replacement.

Hi,

I bought a Walmart battery replacement, car starts fine but the yellow battery warning light on the dash remains on after the car is started. It stays on for a short period 2-3 minutes, and then goes off. I put the battery on a charger an it appears to have a full charge, but the warning light behavior remains.

Thoughts?

Thanks,
Dale

Originally Posted by dgeldart

Hi,

I bought a Walmart battery replacement, car starts fine but the yellow battery warning light on the dash remains on after the car is started. It stays on for a short period 2-3 minutes, and then goes off. I put the battery on a charger an it appears to have a full charge, but the warning light behavior remains.

Thoughts?

According to p. 111 of the 2007 Owner's Manual, when the amber battery warning light comes on "... The battery is no longer being charged. The alternator V-belt is defective or there is a malfunction in the charge current circuit of the alternator..."

This indicator does not directly correlate to the battery's health or charge level; rather, it's an advisory about the alternator/charging system.

It could be as simple as your serpentine belt slipping on the alternator until it warms up. Check the belt tension and have the alternator diagnosed. I think most auto parts places can measure the alternator output.