E70 Increased Battery Discharge while Stationary
 

Does anyone know the cause of this high battery discharge? The dealer still have no clue. They came to pick my car up yesterday with a slide on truck and replace battery. Guess what? after a few hours the new battery got discharge again.

My X5 show multiples messages

1. Increased Battery Discharge While Stationary.
2. Start Assistant Inactive
3. 4x4 system and DSC failed :dunno:

Anyone has the same problem? My X5 is about 2.5 years old MY08 3.0

I had this problem on my 2008 x6 v8. Problem never went away after replacing the battery. I feel your pain, it was very annoying having to reset the time and date. Good luck

Sammydtd,

Thanks so much. I still hope that it can be fix and the same problem never come back. However if it does comeback then I may have to move on to ML 350 Not really a MZB fan, but if BMW still can't find solution it left me no choice. I need a reliable car/suv. :(

So you're going to sell your 08 for a new ML even though you don't like Mercedes? Why not get the new 2011?:dunno: Looks like the 08 was the year with the issue..

Afraid that 2011 still got the same bug as 08.

Electrical problems are worse with MB, not sure why you think that would fix things.

I had similar messages on my E60, they eventually traced it to a loose ground connector.

Being a past owner of a 08 Loaded 4.8i X5 and a new 10 GL350, all I can say is so far, the MB is a ahead of the game. Keep in mind, depends on the driving "feel" your looking for. BMW is no doubt more sporty and stiffer suspension. The GL 3rd row is my main driving factor - seats I can actually use as opposed to the X5. As well, the 2nd row is a little more spacious and the rear dvd + harmon kardon sound system, blow my X5 away. Germans are germans, but the MB is I'd say a little more classy and the X5 is a little more sporty.

Hmm. More to think and compare. But still hope to stick with sportier looks on BMW. Let's hope that my SA can solve these problems on my X5 so that I don't have to switch.

Would definitely consider ML350 if my X5 problems can't be solve. Thanks nynd!

In all fairness, you can't compare the GL to the X5 - two different sized vehicles. BMW does not have anything to compete with the GL, nor the R for that matter. The "3rd row jump seats" are a joke in the X5. I currently have an 08 ML350. Nice truck but it's no X5 - not even close. Side note, I find the sound of the premium sound system in the X5 superior to the HK that MB offers. Different strokes for different folks, folks! :thumbup:

No argument there. We all have differing opinions, hence the reason there are so many different brands to choose from. All said, it comes down to choosing what you like. I do agree in some form, yes, the GL is not quite comparable to the X5 but I think they are close when you speak of 7 seaters on the market. Both are nice vehicles and both I guarantee will have headaches - just a fact of german electronics. Depends on what you prefer driving.

I wrote about a possible fix in April. I had the following parts replaced:
Replaced Battery 61-21-7-594-976 (made in Italy)
Replaced Battery Cable 61-12-9-215-954
Replaced Battery Cable 61-12-9-217-004
Replaced IBS and BST (no part nrs, one is Intelligent Battery System, no idea what the other is).
Not saying this is the solution, but I have not seen an error
message since.

Here is a pic of the IBS (top right).
http://i154.photobucket.com/albums/s...7/IMG_0004.jpg

Here's a better pic. It's the black part with the Rolls Royce, Mini, BMW logos:

http://i154.photobucket.com/albums/s...7/IMG_0003.jpg

OP-

First, threatening this board with talk of "having to switch to MB" is just silly. Seriously. Half of your thread will now be argument on MB versus BMW.... and honestly WE DON'T CARE ABOUT YOU OR WHAT CAR YOU DECIDE TO DRIVE. This forum is not "BMW Corporation". Threatening it will not motivate a solution.

OK?

Now, once you've gone to the SA, keep in mind that there is a notorious issue with drain. Is this original battery? If so, I would just replace it but not at a dealer- save yourself $200. Once the obvious stuff has been checked, there is an BMW SIB for battery drain, and specifically how to test for this. If you allow the SA to decide what they will do next, and you are paying the tab, it can be a lng and frustrating road. make sure you bring this SIB to his attention early on and make sure you have this explicitly listed in a work order. if they fail to do it and ultimately it turns out they have to do it- you have some leverage.

Good luck with getting the X5 fixed. And if not, MB makes a fine car. ;)

A

If battery needs replaced and OP has an 08 model, wouldn't battery be covered under new BMW warranty? No need for purchase from dealer or autozone.

I/some of us US based posters don't "know" what the warranty/maintenance program is, in Qatar...

I recall several posts of people having difficulty getting their batts
"covered" by BMW, even early on, under warranty. Back at the ranch,
I hope the OP's dlr figures out the drain or the problem and gets him
back in shape.
GL, mD

So wrong! While I am a big, big BMW fan (sold my 2009 ML63 AMG to get into a 2010 BMW 750i)...BMW (E70 X5) has way, way more Electrical problems that Mercedes ML. I had both a 2007 and 2008 E70..and they were BOTH electrical nightmares. When BMW and my dealer were working on my buyback package for my first new E70, there were 2 other people also working on E70 buybacks!

Both my 2008 and 2009 ML63 Mercedes had many, many fewer electrical problems compared to both my E70s. My 2 MLs were far from perfect...but the problems were more mechanical. I would confidently say the E70 is more problem prone in terms of electical issues!

Ok, Thanks everyone. Enough said about MZB. :popcorn:

After 3 days in the shop now my SA told me that the dealer is trying to blame the false on me. SA said that their tech team got read out from my X5 memory that I left the ignition in "ON" position 3 times so the battery drain out. How can I leave the ignition in "ON" postion when I remove the key and lock the car everytime. :wow:

The funny thing is that I never even try to listen to my radio when my car is not running. How could these stupid things be on my X5 memory??:dunno:

The first day
They replace battery and reprogram my car. After completion, battery drain out again.

Second day
They were trying to find the cause of battery discharged.

Third day
They finally found the cause of battery discharged (That's what they claim) So, it took them 3 days to fix this memory related problem (which they have just realized on the 3rd day).
Hope that it will be fix for good. I will check my car carefully tomorrow.
My SA told me that there is a long report and I will read it carefully. And yes, I fight for it be a warranty claim.

Thanks so much refusdedog for a great pic. I will also check if they replace IBS.

BMW in Qatar come with 3 years BSI 60,000 km and warranty. So, I'm a bit lucky. Still got another 7 months of warranty left.

BMW SA are crooks... the BMW techies are idiots... never will i buy another BMW do to poor customer service!

I had a battery drain problem also. They claimed that it was the aftermarket stereo system that was installed because supposedly someone spilled some liquid onto a loom of wires. I told them to take pictures of the area before they cut and splice in new wires and what did they do? They replaced the supposedly damaged wires without taking the pics like i asked them to. total cost? $1000!!! i still get the high discharge alert at times. :(

Hey now, don't lump us all together in one boat... I understand why you are upset with what happened, but understand that not all SA's are crooks and not all techs are idiots. If you feel your service adviser is shady ask to be switched to another one of your choosing. If you had a bad experience with a techs work, ask that it not go back to that tech on future visits.

The dealer I work for has some advisers that have been dealing with the same customers for over a decade and are great to deal with, and a few techs there including myself have customers that request us only to do their work. You can fix the situation, and the service department is usually happy to do whatever it takes to remedy bad experiences.

W-

Very true- but from a civilians point of view it is SO HARD to manage the relationship. Often times the dimensions of your screwing only become apparent later, and the dealership 'closes rank' to protect their own... most owners are clueless, and just have to trust what they are told... they don't even know when to ask for help or other opinions...

Also, you work at a good shop. There are some toxic dealerships out there, with predatory policies that induce dishonest SAs to 'shade' the truth and maximize their income - in competition with other SAs to save their jobs.

You're lucky and I'm lucky. But many are not.

A

Yes, we can choose new SA and new dealer. But, what if you are living in a small country like me? Only one BMW dealer in the whole country. Atleast my SA is very helpful and honest. Hope that my car will not have high battery drain message again.

Pick my X5 up yesterday and it seems to be fine. New battery is in black unlike the previous one which was white. The only thing I notice is that the dome light turns off much quicker than before. Other than that my X5 still run great.

The battery was switched over from lead acid to AGM, and the vehicle was programmed for the retrofit. The AGM batteries are better but use a different charging profile from the lead acid hence the programming. And the software also changed up a few things to help with power useage as well.

I apologize Weasel and Ard. Let me direct it more locally.Stay AWAY from MOMENTUM BMW in southwest Houston!! :D

Thanks Weasel!
Can you please enlighten me about AGM battery? What is AGM stand for anyway?
Is it the same like those maintenance free drycell battery in the States? :plane:

Discharge
 

Good luck but my 07 X5 4.8 stayed 8 weeks in the shop over several vists for this. The dealer when stuck has to do the steps that BMW wants them to take and they are very slow. Mine was just waking up and drawing too much current. It does wake up every 70 minutes or so to check on itself.

BMW ended up taking my car back but it took pressure in the form of a lawyer and writing to Munich. That said my 2010 X5 3.5D has been flawless for 4 months now and it was at no cost to me.

I think they concluded it was a battery computer module on my old X5 but they always replace the cheapest parts first. I was on my third battery.

Here's a helpful link to tell you just about all you would need to know about the different battery types and what all the different numbers/ratings mean.

Battery Tutorial

Thanks Weasel :thumbup:

The battery/electrical bug has hit my 2010 35d.
Battery holds a charge for an hour and no help until Tues at the earliest.

Wish I had my old truck back.

My 2010 had the battery discharge the first night I brought it home. I played with the settings and after a few nights I was finally able get it to go away by changing the pathway lighting setting to 0. I've only had the message come back one time and the interesting part was that was after my dealership installed and programmed my hitch. I check and sure enough my setting had been cleared with the new programing and pathway lighting was back on. I turned it back to 0 and have never ever had the problem again.

To get back on topic (instead of comparing BMW to MB), I've had this fault 3x now with my '07 X5 4.8. Each time, I turned off the car, let it sit for a minute, restarted and the fault went away. No replacing the battery - yet.

I've had this happen too and they replaced the battery under warranty. I've read that lockinng the doors (even in your garage at nnight) helps the sensors/modules go to sleep sooner. I'm not sure if this is true or not, but the new battery is still holding up.

It ticks me off that I have to put a battery charger on it over night to protect the battery. That shouldn't happen on any car, much less one that costs as much as these do!

My problem was a dead cell in the battery - but it gets better.

Apparently I don't drive enough and BMW won't cover the battery.

I have only purchased four new BMWs in the last five years and drove all of them the same.

I deal with a lot of battery conditions from Golf carts to the marine
environment and a dead cell has always equated to a fault with the battery, not the usage.

The dealer made good as I will not purchase any more BMWs if I end up paying for this one.

I am disappointed with the quality in this 2010 X5 and will still need to reassess any additional purchases.

Also advised BMW NA of my intentions.

I had to jump my x5 the day after I got it new. But like I said I changed the settings and it went away. I noticed I would go out in the garage after the car had been setting there for several hours and the headlights would be on.

That's interesting...

I see two criteria in the warranty:

"extended use with trips of less than 10 miles"

"no driving from several weeks"

Did they TELL you specifically how you failed these criteria? (Actually might I tactfully point out that the only way they would KNOW this is if you told them)

Pretty common issue with Porsches, as many sit for weeks on end as garage queens...they actually state that you must drive over 6k per year for warranty coverage on the work order when you get a new battery.

Sorry to hear, bummer they are being difficult- next time just tell em you drive at least 11 miles once a week!

;)

A

Actually there is a service function/test plan called "energy diagnosis" which tells all kind of stuff about the battery etc. It shows the battery charge status for the last week, parking profile for the last week, driving profile for the last week, sleep/draw profile for the last month, etc. So it will actually say how many trips are made within certain mileage ranges. This test plan is mandated to be run for any battery issue by BMWNA warranty dept. and they will not cover batteries that are failed due to nothing other than driving profile... So lying to them won't work, they see all the info stored in the vehicle.

Good to know...although I wouldn't lie, I'd just not say.

Does the stored driving profile match the criteria in the warranty statement?

My guess is the 'driving profile' software is not as nebulous as the language (I am quoting here):



It would be interesting to see how BMW applies their software derived rules to the language of the warranty.

Thanks W-

A

It doesn't tell us what order the trips are in, just tells us how many trips in each mileage segment. If you want to sway it in your favor for warranty coverage on the battery just make a few higher mileage trips (15-20 miles) before you bring it in so they can't call it short trip death. But the higher mileage trips will put a better charge on your battery anyways so it might not act up after that anyways.

Agree to all of the above. I always have a lot of 6 to 12 mile trips. That is my pattern and has been for years - even before buying BMWs.

What their test ignores is a battery that develops a physical fault not due to usage which was my case.

It would also help if there was a low battery warning if their battery's fail that easy.

My sister drives so little that I bought her a battery charger since her battery is dead half of the time. Three years latter - same battery.

I had the 'high discharge' warning for several times now in the past weeks, so I drove to my local BMW dealer and had an 'energie-diagnosis' done.
Results showed;

1) too many short drives (out of 209 drives in 35 days, 148 shorter than 5 kilometers)
2) a battery that was only charged to 44% (40-49% in the last 5 days)
3) 41827 hours of battery usage (seems a lot..??) range of charge was most of the time in the 60-80% range as it should be). Normally the battery is charged to 80%, rest is done by braking-energy (efficient dynamics)

The technicians told me that there was nothing wrong with alternator and or leaking currents, nor was there a problem with the (3 year old) battery. Their advise was to change my (2007 OEM lead/acid standard BMW-Varta (white housing)) battery to an AGM Varta (black housing) together with a software update (different charging protocol).

They also told me another interesting thing; the first range of AGM batteries (2008 series?) had a capacity (?) problem and almost all of them have been replaced or will be replaced in the near future (??)

I guess at my next service I will change my battery, but for now I will get my Ctek charger, as the guys told me that my driving-pattern is absolutely not sufficient for charging my battery enough...
In conclusion: BMW has only recently recognized that the capacity of their OEM batteries is not sufficient for the kind of heavy usage that the average X5 has nowadays......

I had a 1992 Ford Explorer that was used for a year only for less than one-mile round trips to the coffee shop each morning -- not a single battery problem.

I have a 2005 Ford Focus which is used primarily for short trips, typically less than 5 miles -- not a single battery problem, and still on the original battery with 67,000 miles on it.

If BMW cannot match Ford electrical system engineering, perhaps they need to fire a few engineers and hire some from Ford.

Now, some might say, "But gee, BMWs have such a large number of electrical accessories and sophistication that the electrical demand is much greater." Sure... but you have to keep the priorities straight, and the first priority for a vehicle is to start and transport people from point A to point B. And if you can't keep a battery charged with a 250+ HP engine if the trips are less than ten miles, it is time to hire some new engineers.

Since the vehicle system apparently already monitors battery voltage and length of trips, I would expect they could have simply taken the small weight and cost penalty, put on a higher capacity alternator, and programmed the charging system to be more aggressive in charging if it sees a lot of short trips and/or falling battery voltage.

For whatever reason, BMW seems to be very stubborn to admit errors and fix problems like this, and it will likely be around until the next generation X5, when they will fix it with a higher capacity charging system with a more sophisticated charging program.

My guess is that BMW made the charging capacity too low and slow so that they could gain a bit on the MPG test cycles that governments use for rating the vehicles. But that's just a guess. It is also possible that BMW electrical system engineers are incompetent.

Great post, useful info.

So either willfully negligent or incompetent?

:thumbup:

A

PS Must have hired the BMW Navigation Specification team to design the charging system once they were done choosing TeleAtlas....

I fully agree, it is an automotive brand's first priority to produce a reliable car. Now we are not talking about Peugeot or Renault, it is BMW, and as a customer with more than 15 years of BMW experience I know that the engineers in Munich will not think about an electrical system once, not twice, but three times. You could be right that emission demands could be a reason, but from what I heard at my local dealer, it is that BMW already implemented an complete electrical system that is fitted for an AGM-battery in the 2007 (and early 2008?) X5's. Unfortunately, when they put their first AGM (VARTA....) battery in, it also couldn't keep charge.... From what I understand; if you have the AGM-02 (also Varta?) installed, together with the software update (2-6 hours....) the problem should be fixed.
Still I agree that BMW should have thought about this earlier, it is the same story with the 7 series a few years ago, almost all of them stranded (even the director of BMW Netherlands on one of our busiest highways) with a dead battery.

I have a 2010 X5 and it got the dreaded message after three short trips, preceded by nothing but highway trips of more than an hour in duration.

BMW have not fixed the problem yet, at least not on 2010 models.

I now make sure I put it on the CTEK charger once every couple of weeks, which is absolutely ridiculous for a vehicle in this price range.

Next time around I think it's going to be a Ford, rather than a BMW.

I can understand your anger....! Ridiculous.... Should not happen with a brand new X5.....
But I think you have a different problem. I guess you have the AGM-02 battery and new software, so it could be your X5 is experiencing leak current. Did your dealer already check the 'known' issues (i.e. blower-motor resistor/satnav/cd changer waking up the (sleeping) X5?)

Very interesting posts.

While it could be incompetence, I think I would classify it as an organizational incompetence rather than a individual engineer incompetence. Think of how Ford would have specified an alternator: they used one with xx amps on the last model, so they used the same on the new model. Every now and then they will move to a smaller and lighter battery for weight saving, but I suspect that they simply don't use overcomplicated charging profiles and such. They also know how their customers use their vehicles.

BMW must have a room full of charging system engineers. They invent variable charging profiles, customized to different battery types. They turn off the alternator when they can, for acceleration figures (witness efficient dynamics). They assume nobody would drive primarily 5 km trips, because they don't in Germany. They have sleep programs that sometimes don't run because there are miniscule current draws keeping the vehicle awake. And the result is that it is all horrendously complicated and interconnected.

Penguin suggested that BMW has trouble admitting mistakes. I agree. I think the specific mistake they are having trouble with is admitting that more engineering doesn't fix a problem that has at its root, too much engineering.

p.s. When you use your CTEK, do you use it at the AGM (14.7 volts) setting? It is marked with the * (also for use in winter conditions)
If you charge your AGM at normal setting (14.4 volts) you will not charge your battery completely.

Of course. I am a firm believer in reading manuals.

I agree. I think it is a German thing (....;)) They know they make good products, but when something is wrong they just can not believe it is true.... Could it be arrogance...?

:thumbup:

Perhaps. But maybe just plain old stubbornness...

For a decade (or more) in the 1970's/early 1980's, BMW used spring-loaded sidestands on their motorcycles. Everyone constantly complained as it is quite difficult to hold the sidestand out with your left foot while gently tilting the bike onto it. BMW's answer was that a proper rider should dismount the motorcycle to the left before putting the sidestand down.

Think about it. Particularly when you are touring and have sidecases and a bunch of stuff strapped onto the rear of the seat.

It was so bad that there were at least 3 companies selling replacement sidestands that bolted onto the frame, were ugly, and costly ($75-150 in 1981 dollars). Yet, they sold a lot of the ugly things, including one to me, because of the bad BMW design.

BROWN Sidestand BMW R100RS,R75/5,R100S,R80RT,R90S,R80/7 - eBay (item 380299314100 end time Jan-13-11 10:49:41 PST)

Finally when they came out with the K series of bikes they stopped using spring--loaded sidestands... it only took a decade for their customers to pound it into the engineers' heads.

In the early 1990's when BMW added power-hungry ABS systems, the bike began having under-charged battery problems. BMW blamed it on the riders taking too many short trips and/or keeping the engine RPMs too low. Sound familiar?

It got to the point that they were giving a free BMW 3 amp battery charger with every new motorcycle (I got one with my 1991 K75S). After 2-3 years of this, they stopped giving away the free battery chargers and no one had any charging problems. Oh, and there was a new, larger alternator attached to the engine when they stopped giving away the free battery chargers.

BMW representatives and presenters at the BMW National rally never, ever admitted there was a problem with the sizing of the charging system. I suspect if you asked them today, they would still deny it, and blame it on the riders' riding style.

:iagree:The japanese refer to this as "saving face" --- I'm wondering how that translates into German???:rofl:

$5 word I can't pronounce!

Great story, sounds very, very familiar..... Is there any way we can 'prove' the X5 alternator is too small? i.e. can we calculate out 'total' current with all devices running, and do we know the maximum output current of our alternators? I am going to see if I can find this info.

I don't think the alternator is too small. If it was, then everybody would have a flat battery after starting the car a few times.

The problem is that it doesn't charge often enough and strongly enough, because of a computer program that tells it to disengage or operate with reduced parasitic load, so that the driver can get to 100 km/hr a fraction of a second quicker, or so that the vehicle gets better mileage on a test cycle.

It isn't a peak charge problem, it is an average charge problem.

That depends on 1) how the battery was charged at first 2) how many electrical 'users' are switched on during driving 3) how long the drive is 4) the 'general' state of the battery. Because there are so many variables, the problem is how to pinpoint the exact cause.
If it is the computer telling the alternator not to charge the solution would be relatively easy; a software update (as is done with the switch to AGM-02 batteries). If it was an emission c.q. more power/better mileage, I would think that the engineers in Munich would have had a trick to get better grades when tested (as is often done....), but not let customers get flat batteries.....
By the way; the battery is supposed to get charged to only 80% because of the Efficient Dynamics, rest has to be done by braking. It could also be that exactly this is our problem.... As you said, not charged strongly enough. And as we all know, this will eventually lead to a substantial shortening of the battery lifespan....

Sadly, this is just a direct translation of "Saving face", and not a used saying or word :)
:stickpoke

Curious, what's the normal voltage of an X5 when the vehicle isn't running and there is a load? I checked the X5's voltage this afternoon with the engine off but all electrics ON; vehicle has not been driven in a couple days: 11.8V.

The battery was just replaced on 23. Dec 2010. One thing I noticed that's new (compared to before flat battery) is that the P is not illuminated/displayed on the gear shifter until I put the key into the dash slot.

But Alternator output is dependent upon RPM. So you are right, it isn't a peak charge problem, but still may be an undersized alternator problem in that the alternator cannot provide enough output at lower RPM to fully-charge the battery on short trips, e.g., the software may be asking for max charge from the alternator, but the alternator cannot comply due to low RPM. I suspect that there would be no problems with batteries going dead from short trips if people put the transmission in manual mode on short trips and kept the engine RPM's at 4,000, even while stopped at stoplights.

Here's the curve for a couple of alternators, and you can see that at 2000 - 3000 RPM (shaft RPM, not Engine) the output is much less than Max:

http://image.superchevy.com/f/902272...c_alt_03_z.jpg

http://www.vortexbuicks-etc.com/CS144.jpg

I don't have the X5 pulley ratios, so I can't translate alternator output to engine RPM, but the effect is there, it is only a question of to what extent.

To help avoid the battery issue, I tend to put the transmission into Sport mode if I know I am doing short trips.

I would say that your (1) and (4) are conditions, not causes.

(2) is related to load, and (2) is related to charging time. BMW will have assumed a certain load, and a certain profile during the drive to recharge the battery.

I may have accidentally led you astray, I was simply trying to say that if the alternator was too small, then all owners would have the problem. Many of us have never had a flat battery, ever, in any modern BMW. Load would vary with the number of starting cycles (the other running loads are pretty small), and the remaining variables during operation come down to how people use the car when the battery is being recharged. The last variable is what happens when the car is not being used, and whether reserves are being drawn down.

Absolutely agree. But I would have thought that with a 2 or 3 to 1 pulley ratio (just guessing, but I think that is the range) then anything above engine high idle should be contributing to the charge.

Yet another reason for manual transmissions, and regularly running the engine close to red line once it is warm.

For those interested, here is BMW's Energy Management Strategy for the E70, dating back a few years.

http://www.bmwmotorsports.org/pdf/e7...Management.pdf

Executive Summary: Penguin's Explorer, referenced above, had a voltage regulator that read battery voltage, and decided whether to charge the battery or not. Worked pretty darn well. OTOH, the above document takes 35 pages to explain when the alternator should be charging the E70, or not.

True, unless BMW chose a ratio at the bottom end of the range to improve power and fuel economy, figuring drivers would not make short trips with heavy electrical loads, such as headlights? (Or idle the engine a long time) Essentially putting a mild "underdrive" pulley on the engine as stock?


Note item #1 under the section labeled "Some Commonly Expressed Concerns about Underdrive Pulleys:"

UDP Tech

It's a Mustang in this link, but the concept still applies.

Yeah, it did. I had it for 198,000 miles and 19 years, and it only had three batteries, counting the OEM battery. And those two replacements were preventative, as I didn't want to be changing it in a parking lot in the Winter at night ( one replacement after nine years and the second replacement after eighteen years.) So it's not like an "unsophisticated" charging system hurt battery life at all.

As one of my old bosses use to say, BMW's charging system just might be "one half too smart."

The E70 shows both 180 amp and 220 amp alternators, depending on options (rear seat heating brings it up to 220 amps). It may vary further with different model years. In any case, those aren't small alternators.

I am with your old boss, I think it is a complexity problem.

This is actually a BMW training manual used in schooling techs, as good of info as it gets for most things.

Just as an aside, and certainly not even in the same 'family' of cars, but the alt in my '02 C5 is 110 amp, (& made in France :D)...the interesting point is that our C5 'cruises' at 1500 -1700 rpms, (not 'high rpms), yet that smallish alt seems to do a good job of keeping the electrical system/batt running well. No food fight, just interesting to me.

Maybe the same engineering group that does the window regs, works on the 'electrical sys' of Xs, on the weekends. ;)
GL, mD

And with that amount of complexity, just think of the job security for our beloved BMW techs!

(The training manual is posted under the Online References tab, and covers all of the E70 systems, for those interested)

One of the next things I'm going for training on is the active hybrid, which I'm sure will make this charging system look like an old 1 wire GM alternator... Just the transmission in the active hybrid is amazing enough.

Great info JCL, thanks.
I am going to really get into this, talk to the BMW techs and get back at the forum.

Do you have a link for that Please?

If alternator is not running and all electrical else is on it sounds like a reasonable voltage. Rule is; when battery is measured without load and not charging 'full' would be 12,89 V and higher, 'empty' would be 11,89 V and lower.

Across the top of the forum page, there are tabs for Home, Forum, Articles, How To's, Online References, FAQ, and User CP. It is in Online References. If any members can't see all those tabs, it is likely because they aren't Premier (paying) members. Not sure exactly which benefits come with Premier Membership any more, but I can see them all. Within Online References, select PDF documents, then E70.

If you see the link I provided, for the Energy Management section, you can also use the navigation tree on the left side of the page in that link to access the other sections of the training manual.

I had this similar problem a few month ago.... My dealer done a software update and the problem is gone.

220 amp alternator
 

Has anyone replaced their 180 amp alternator with the 220 amp alternator to see if this solves the problem? Is this a bolt in swap? Do you need a different belt?

Thanks for any info.
Mike

I am starting to see the message "increased battery discharge" with my 2012 X5 that has less than 12K miles. Disappointing.

Just at random times?