[joro2077]

Here's something from m3post:

01-01-2011, 02:53 PM * #12
Technic
Major General
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Drives: 2012 E92 M3, 2010 CC
Join Date: Apr 2005
Location: Ft Lauderdale, Florida

Posts: 9,429
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2004 M3**[0.00]

Well, this is slightly more complicated than it seems.

The reason of the battery registration is that BMW uses an "intelligent" alternator variable algorithm that monitors the battery condition (charge, rate of discharge, etc) and simply shuts on and off depending on this condition. That reduces engine load thus increasing efficiency -power and economy.

When you replace the OEM battery you in fact are not telling that algorithm that the battery adapted values stored so far no longer apply -they were collected over a period of time from the old battery condition. So the "old" algorithm continues to do its job although the variable values changed. This could either under/over charge your new battery just because its charging/discharging characteristics not necessarily will have to match the old battery's.

So the sole purpose of the battery registration is to update that algorithm to the new values, by starting over the collection of adaptive values from the new battery so it is charged/discharged exactly -or close to it- to its most particular efficient capacity.

Sometimes it seems that the battery registration was not necessary when there are no problems with the new battery install. That's most probably due to the new battery condition pretty much matching the current alternator algorithm and that you are not asking too much from that battery... in other words, just luck. Sometimes it really messes up the new battery after awhile as the current algorithm keeps the battery under/over its real capacity.

My suggestion is simple... try to find an Autologic shop and get the new battery registered just in case. It takes less than 5 minutes -just press "Register" in the screen and that's it- and most probably the guy there will do it for free if you ask nicely (I did that). In the worst case is half an hour job or even less.

The dealer as always is making this like a big job which it isn't. By the way, I'm using a Sears Die Hard battery instead of OEM.
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[litz4244]

It's just not for alternator algorithm. Part of it is but there is alot more to it then just that but it's alot more then I care to type since nobody cares anyway and people will do what they want which is there choice since its there car.

[ajsalida]

Originally Posted by litz4244

It's just not for alternator algorithm. Part of it is but there is alot more to it then just that but it's alot more then I care to type since nobody cares anyway and people will do what they want which is there choice since its there car.

If you have some links please post them. A lot of this scary battery stuff does not pass the basic smell test. For example, suppose you run your battery low somehow, and drive it around that way for a few weeks. The car has now adapted to your battery.

Then you put it on a trickle charger for a couple days, charge it up to full charge. Do you need to tell the computer that? Re-register the battery? I don't think so. So how is that different from swapping in a same type new battery?

I was having all kinds of problems when winter started, low battery errors. Dealer said maybe replace battery, that I didn't drive it enough, not a warranty item though. Well I finally put it on a 2 amp charge til the light showed green, each fall since. No more problems.

Batteries should last 7-8 years if properly cared for. The e9x clearly has some charging algorithm in it designed to do nothing but squeeze a couple 1/10 better mileage out here and there. It is not that smart and seems to get lost when charge is a little low, and does not charge enough to bring the battery up to full charge.

Anybody looking to replace their battery should at least try a 2 amp charge for a day or two and see what happens. And I suspect swapping a like-kind and same AMP/hr battery will do no harm, but I do not know that for a fact.

[litz4244]

I will not post any Info due to being copy righted bmw documents not to be shared with third parties. Sorry. The reason you where getting the time resetting and the high drain message was because the battery was dipping below the threshold and tripping the 30g_f relay causing the message. Putting the trickle charger on the car of course solve that because its not letting the weak battery dip below that threshold. Just because I don't recommend using an after market battery doesn't mean you can't. They even give you the ability to register the after market battery. Just make sure it's the same ah rating. But as for you saying it could re adapt to a new battery it takes along time. It just doesn't do it after one drive cycle. Believe what you want but there is alot more to it then you think. I understand alot of people bash on the dealers on this post but I find it funny when it's a hard issue these Indy shops can't figure out they still come to the dealers. I understand there are some crappy techs at dealers but there is crappy techs everywhere. Just like at all jobs in life. There are good and bad employees.

[ajsalida]

Originally Posted by litz4244

I will not post any Info due to being copy righted bmw documents not to be shared with third parties. Sorry. The reason you where getting the time resetting and the high drain message was because the battery was dipping below the threshold and tripping the 30g_f relay causing the message. Putting the trickle charger on the car of course solve that because its not letting the weak battery dip below that threshold. Just because I don't recommend using an after market battery doesn't mean you can't. They even give you the ability to register the after market battery. Just make sure it's the same ah rating. But as for you saying it could re adapt to a new battery it takes along time. It just doesn't do it after one drive cycle. Believe what you want but there is alot more to it then you think. I understand alot of people bash on the dealers on this post but I find it funny when it's a hard issue these Indy shops can't figure out they still come to the dealers. I understand there are some crappy techs at dealers but there is crappy techs everywhere. Just like at all jobs in life. There are good and bad employees.

*sigh*

The DEALERSHIP did not understand how the charging system works. They recommended a new battery when one was not needed. The MANUFACTURER designed it so it flags a code for low battery (and then tells the techs to replace it) when that is clearly not the case and not needed. The smart charging system is not very smart if it can't keep a good battery charged. I am missing where all the hidden geniuses are in this scenario.

This was the biggest dealership in the state (by far) SCHOMP BMW Denver. I think the last place I'd want to go with a complex problem to debug is the dealers, they are good at by-the-book things and if the book is wrong then you are screwed. Look how many people had HPFP problems with bandaid fixes and multiple failures until a solution finally came out.

For big jobs under warranty certainly that's where I'd go. But to make a blanket statement about the quality of dealer techs @ debugging problems, you either don't read much on this forum or you work for a dealer (or both).

[litz4244]

Lol obviously you want to think what you want but you are seriously misinformed about the power management on these cars and I am not going to sit here and argue over a web forum about it.
There are good and bad techs everywhere so I do understand where your coming from not arguing that. But yes I do read the forums and some of the technically discussion is so inaccurate and dumb I can't help but to laugh.

[ajsalida]

Originally Posted by litz4244

Lol obviously you want to think what you want but you are seriously misinformed about the power management on these cars and I am not going to sit here and argue over a web forum about it.
There are good and bad techs everywhere so I do understand where your coming from not arguing that. But yes I do read the forums and some of the technically discussion is so inaccurate and dumb I can't help but to laugh.

Actually you are here arguing and so why don't you just tell us what you know for a fact with details, instead of making unsupported statements and waving your hands & asking us to believe you.

I believe what verifiable facts and experience tell me, not what I want to believe. And the verifiable facts & direct experience tell me the algorithms are not that smart nor are dealer techs.

If you have some evidence then please present it.

[litz4244]

I already told you in my previous post why I will not post the documents. For somebody so hard on facts your voicing your opinion about the whole subject without any facts. Believe what you want I was just putting my 2 cents in. I have plenty of experience with this.

[ajsalida]

Originally Posted by litz4244

I already told you in my previous post why I will not post the documents. For somebody so hard on facts your voicing your opinion about the whole subject without any facts. Believe what you want I was just putting my 2 cents in. I have plenty of experience with this.

And you are not supplying any facts at all, either. Please post a detailed explanation of how it works, you don't have to post documents. You are no better than anyone else stating an unsupported opinion otherwise.

This forum has a lot of smart people on it and we all benefit from their shared knowledge & experience. We all want to learn. Well most of us anyway.

[Javier]

Does anyone know if the battery can be registered with a BT cable?

And please do share any info you can, lots of people are interested. Remember lots of people read the forums for info, only a fraction actually post.

[Tzu]

Originally Posted by Javier

Does anyone know if the battery can be registered with a BT cable?

And please do share any info you can, lots of people are interested. Remember lots of people read the forums for info, only a fraction actually post.

Yes, there is a battery registration task as well as a battery adaptation reset IIRC. They both do the same thing says the coding forums.

[335xi Kevo]

Originally Posted by litz4244

I already told you in my previous post why I will not post the documents. For somebody so hard on facts your voicing your opinion about the whole subject without any facts. Believe what you want I was just putting my 2 cents in. I have plenty of experience with this.

Wow dude, your really aren't as important as you think you are. BMW isn't going to "sue" you over posted images. Jesus, the vw/audi forums are filled with screen shots, hell I have a ripped ETKA can find any part on the planet. Everyone post bently screens etc. I hope you dont speed cuz thats just as risky!!! Ohhh no!!!!!! That is the most absurd thing I ever heard.

[F104]

The algorithm tries to figure out what the charge is the battery can hold, while knowing it will reduce to zilch over say 5 years. The battery management sensor continuously looks at the battery and tries to figure out where it is on that assumed 5 years life, and whether it is shorter, or longer.

Why this complicated system? Because BMW has "efficient dynamics" on some models. What is does is keep your battery at 90% of capacity, such that when you coast or brake it can use that alternator to charge the battery by 10% up to 100%, without using fuel. And then during acceleration it can stop charging the battery if it thinks it has the spare capacity. For that to work it needs to know if the battery it is brand new, or old, or anywhere in between those two levels, as well as battery size and type

Overcharging? I don't think the system can overcharge. My battery has been bad for the last 3 years. Won't show more than 11.8 - 12.2V in the morning, Alternator is charging it continously wih 14.8V. It hasn't exploded yet, it doesn't run hot or anything, as current simply doesn't flow into the battery. Starts fine though even after two weeks..

I can see my voltages all the time. My OBD reader can plot them too. Actually my system drops every 20 seconds to 14.2V or so, to jump back to 14.8 as it sees the battery doesn't keep up . What it should be doing if the battery was ok is let it drop to 13V or so (bear in mind the surface tension of a just charged battery, hence more than 12.8 for a good battery), Then charge at about 14.2, and wait for a braking event to go up to 14.8.

[kenneth]

My car is also 5 years old with 60,000kms. It sometimes goes weeks between usage. I recently noticed the battery sign light up on the dash. I plugged my trickle charger to it and indeed the charge was below 50%. After an afternoon and overnight Charge battery is back to full and working properly.

I did the same thing a year ago on my VW car and the battery is still working as we speak.

[oshusttoley]

i dont get a batter low sign...i get "increased battery usage" or something and the clock time resets.... does this mean i also need a new battery? if so where can u buy an oem one beside the dealer? i dont wana spend 500 for a new battery and when i replace it, my car is coded....would all this go back to stock?

[orionredwing]

After much research on cheap alternatives, I installed a Walmart battery a year ago and registered and reset adaptation with my BT cable.

No problems so far. I also like to hook up my trickle charger about once a month, since local driving to/from work may not fully charge it.

So far, the CHEAP battery works w/ no problems. 1 yr and counting. Only time will tell At about $120, if it lasts at least 3 yrs, it's totally worth it imo So my suggestion to the OP is hook it up to a trickle charger first (I use a cheap and reliable one from CTEK). If that doesn't work, get it replaced.