Interesting service visit - battery draw down w/o warning

[ciaranob]

UPDATE: Useful info on battery voltage via BlueDriver OBDII tool - see thread further in.

Well I finally got my car back today after a week at the dealership. Was in primarily to replace a driver seat leather base due to premature unravelling of the leather stitching - replacement near perfect but not quite - good enough.

However, midway through the week the techs had a general systems scale look at the car as I had reported a few instances where a 'Drive Train Malfunction' and some other warnings had popped up randomly a few times since ownership (mostly occurred I think from a rapid shift to rear on startup and invariably never came back after shutdown and subsequent startup).

All systems checked out 100% AOK so that was good BUT they found that both my headlight assemblies and more specifically the driver modules that control them were not going properly to sleep when car was shutdown and by staying on were bleeding energy from the battery the whole time!!!

They looked back through the history of the car and at times the battery was apparently below 40% charged. I told them (and they could clearly see) that I had a wired Dash Cam (even though it has the power magic controller that will avoid any battery drain and was only on the car less than 30% of its life to date) but they confirmed this had nothing to do with it at all. It was it turns out a pair of faulty headlight driver modules!! Bizarrely I never got a single system warning of low battery charge since ownership (Sept 2014) and never had an issue starting the car (suspect if I lived in Calgary the story might have been different! ). A full check of the Lith-ion battery says it is AOK and accepted a full charge. They ordered a pair of replacement driver modules and installed them which seems to have done the job.

Just a heads-up that there was again no warning whatsoever of this draw down (oblivious to me) and that it was only after a specific full systems check that it was even diagnosed. So next time you are in maybe have them check these puppies out. One negative is that a number of my coding mods were switched back to defaults after the tech programmed the new drivers and so will need to get those items re-coded - have a PM into Shawn and hoping he can help out!

Just thought I'd share as had not seen anything similar on the Post to date and as you all know these batteries cost a fortune to replace if out of warranty (at least now I have a record of poor battery charge due to faulty components under warranty).

Cheers, C.

[ciaranob]

Wow - amazed that no one finds this relevant

I have to believe that the odds of my car alone having this issue would be slim to say the least but maybe so. Remember no warnings whatsoever and no apparent effect on car (mine is a daily driver) yet less than half charged. A weekend car might see a more drastic result.

[GrussGott]

ha, I do!

I'm curious why this kind of diagnostic (check battery draw history) wouldn't be part of the standard Xk mile check up, especially since something like this could strand you and it's so easy to check.

bummer about the coding!

[paliknight]

My car only notified me of a low battery when it dropped below 20 or 15%. Then it recharged to around 50% with extensive driving then 100% at the dealership. I had the car sitting for 2 months though.

[apexit]

Same happened to me, same headlight i think too. A week later my cars battery died and i ended up with a new battery and alternator. So far no more issues. 2015 with 33k on the clock. I'm hoping they fixed it for good because if it took 30k miles to show up then the next incident will be out of warranty.

[aboulfad]

Originally Posted by GrussGott

...
I'm curious why this kind of diagnostic (check battery draw history) wouldn't be part of the standard Xk mile check up, especially since something like this could strand you and it's so easy to check.
...

Read this post and subsequent ones. It is intriguing that the OP had no check control msgs, as the car monitors standby current in rest mode... (read closed circuit monitoring pdf in linked post).

One can easily execute all these jobs with ISTA (energy diagnosis) that provides various infomration on the health of the battery (histogram of SOC, circuit monitoring, charge history, driver driving pattern,...)

Usually, those jobs are only executed by techs only if customer complains of a problem related to car electrical system including battery.

[ciaranob]

Man it waits til 20% - seems ridiculous - you would also think that they could have put a simple visual/digital read out of battery status in the iDrive (prob eat my words but don't recall that being there correct?)! Mine is a daily driver and in Houston i.e. no winter down time so driven continuously since picked up in the US after ED.

Originally Posted by paliknight

My car only notified me of a low battery when it dropped below 20 or 15%. Then it recharged to around 50% with extensive driving then 100% at the dealership. I had the car sitting for 2 months though.

Interesting that yours was also a 2015 so maybe a production issue w.r.t. the driver control modules for the headlights? Hear you re warranty issues - hence my comment re at least having one instance noted during warranty.

Originally Posted by apexit

Same happened to me, same headlight i think too. A week later my cars battery died and i ended up with a new battery and alternator. So far no more issues. 2015 with 33k on the clock. I'm hoping they fixed it for good because if it took 30k miles to show up then the next incident will be out of warranty.

[ciaranob]

Curious indeed - the tech also mentioned or at least it is listed in the maintenance write up that there were periods of 0-40% charge level!! Assume above zero but again no indication from onboard systems - madness I tell you

Coding no big deal as have Shawn Sheridan the master in my neck of the woods and has agreed to help me out again - awesome guy!

Originally Posted by GrussGott

ha, I do!

I'm curious why this kind of diagnostic (check battery draw history) wouldn't be part of the standard Xk mile check up, especially since something like this could strand you and it's so easy to check.

bummer about the coding!

[ciaranob]

Intriguing yes - I need to go look at the iDrive feedback but again don't recall anywhere you can 'real time' check battery charge status - but if indeed the case it is nuts that the car doesn't let you know through std messaging of a sub 50% charge state imo.

Originally Posted by aboulfad

Read this post and subsequent ones. It is intriguing that the OP had no check control msgs, as the car monitors standby current in rest mode... (read closed circuit monitoring pdf in linked post).

One can easily execute all these jobs with ISTA (energy diagnosis) that provides various infomration on the health of the battery (histogram of SOC, circuit monitoring, charge history, driver driving pattern,...)

Usually, those jobs are only executed by techs only if customer complains of a problem related to car electrical system including battery.

[aboulfad]

Once I was using tool32 for few hours without a charger, and when I came back to my car I got in the instrument cluster a message that battery charge is low, so maybe you missed the message or it never got displayed for you.

And no, you can't check the battery status in iDrive, but you can check the battery voltage using the hidden OBC in the cluster. (But that won't help anyone as LifePO4 retains 13V for very long time, see pic from BMW ISTA docs)

PS: if you ever see Shawn f2f, buy him a single malt on me

[ciaranob]

I am very attentive to my car damn near OCD in respect warnings so honestly doubt I would miss this - and presumably as the voltage apparently varied up and down through life of car to date I should have received more than one notification - positively weird - perhaps I need to check with the dealership tech on why I did not receive a warning!

Have met Shawn a couple of times, solid guy - mine was the first M4 he ever coded ! Will pass along but can tell you now the man simply refuses any sort of compensation - may have to sneak a bottle into his car

Originally Posted by aboulfad

Once I was using tool32 for few hours without a charger, and when I came back to my car I got in the instrument cluster a message that battery charge is low, so maybe you missed the message or it never got displayed for you.

And no, you can't check the battery status in iDrive, but you can check the battery voltage using the hidden OBC in the cluster. (But that won't help anyone as LifePO4 retains 13V for very long time, see pic from BMW ISTA docs)

PS: if you ever see Shawn f2f, buy him a single malt on me

[aboulfad]

I am sure if your hook up ISTA and run the closed circuit monitoring (and if they didnt reset it), then you shall see the offending circuit ! You can also drain your battery and watch for that message

PS: Shawn is special , just make sure it is a bottle of single malt, not blended stuff

[04RC51]

Originally Posted by ciaranob

Wow - amazed that no one finds this relevant

I agree! This thread needs more outrage! A very unusually low amount of outrage for this Forum.

I had my dealer try to ding me for a battery on my E92 until I told them there was a service bulletin on my build date range. Not relevant but whatevs.

[paliknight]

Originally Posted by ciaranob

Man it waits til 20% - seems ridiculous - you would also think that they could have put a simple visual/digital read out of battery status in the iDrive (prob eat my words but don't recall that being there correct?)! Mine is a daily driver and in Houston i.e. no winter down time so driven continuously since picked up in the US after ED.



Interesting that yours was also a 2015 so maybe a production issue w.r.t. the driver control modules for the headlights? Hear you re warranty issues - hence my comment re at least having one instance noted during warranty.

No it was actually my 2016 M4. But that was really my fault though since the car had been sitting for 2 months and I did not disconnect the battery. But Im sure it doesnt warn you until it reaches very low (somewhere around 20% or so). Luckily my battery recharged without any issues so cant complain. but i do have a bunch of electrical problems that keep coming up. iDrive unit was replaced recently, and now I keep getting errors for the pedestrian system crap and the collision warning system crap. Not sure whats going on.

But there definitely isnt a measurement in iDrive that gives you a reading of the battery. it just tells you if its fine or low. FML.

[ciaranob]

So recalled that my BlueDriver OBDII (bluetooth) reads voltage but was not clear on exactly where it was reading it from - enquired re specifically the M4 and got this info back from them - pretty useful (cool tool and one of the better ones re access to actions on codes read etc. and in plain english!):

Quote
"For your M4 BlueDriver will show the input voltage at the DME: either alternator or battery voltage depending on whether the engine is running or not.

The full list of live data for your car is:

I/M Status
Fuel System Status
Calculated Engine Load Value
Engine Coolant Temperature
Short Term Fuel % Trim – Bank 1
Long Term Fuel % Trim – Bank 1
Intake Manifold Absolute Pressure
Engine RPM
Vehicle Speed
Timing Advance for #1 cylinder
Intake Air Temperature
Mass Air Flow Rate
Absolute Throttle Position
O2 B1S2
OBD Standard
Time Since Engine Start
Distance Traveled While MIL is Activated
Fuel Rail Pressure (diesel)
Commanded evaporative purge
Fuel Level Input

1. of Warm-ups Since DTCs Cleared
Distance Traveled Since DTCs Cleared
Barometric Pressure
WRO2 B1S1 (l/mA)
Catalyst Temperature Bank 1, Sensor 1
Current I/M Monitor Status
Control Module Voltage
Absolute Load Value
Commanded Equivalence Ratio
Relative Throttle Position
Ambient Air Temperature
Absolute Throttle Position B
Accelerator Pedal Position D
Accelerator Pedal Position E
Commanded Throttle Actuator
Current Fuel Type
LTFT 2nd O2 B1 & B3
Engine Oil Temperature
Intake Air Temperature Sensor"
EndQuote