E70 Increased Battery Discharge while Stationary

[Penguin]

Originally Posted by RRE70

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.

[ard]

Originally Posted by RRE70

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......

Great post, useful info.

[ard]

Originally Posted by Penguin

..... It is also possible that BMW electrical system engineers are incompetent.

So either willfully negligent or incompetent?



A

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

[RRE70]

Originally Posted by Penguin

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.

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.

[Penguin]

Originally Posted by RRE70

...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.
.

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.

[RRE70]

Originally Posted by Penguin

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?)

[JCL]

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.

[RRE70]

Originally Posted by Penguin

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.

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.

[Penguin]

Originally Posted by RRE70

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)

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

[RRE70]

Originally Posted by JCL

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.

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...?