Clock reseting --:-- Warranty? - Australia
 

Hi all,

I have recently purchased a x5 3.0d with low kms. Within a day I started to experience the clock reseting issue. I have read through the various threads and wanted to see if anyone in Australia could share their experiences. Why ? I called the dealer, and they told me that is was due to my driving pattern. Short trips, the battery doesnt have time to charge up, therefor the car starts to shutdown some of its features. Though that may be true...it find this unacceptable. Has BMW acknowledged this as a known issue and under warranty what should I expect from the dealer.

thanks !

I also would find this unacceptable. If short trips are enough to do this, then either BMW (a) under-sized the alternator for the electrical system, or (b) has gotten some alternators that are not putting-out their rated amperage.

But first off, find-out if the battery is weak or undercharged by measuring the battery voltage with a voltmeter.

This has a table for approximating the battery state-of-charge by voltage:

Battery FAQ

But the best time to measure the battery voltage is after it has been sitting all night -- right after you stop, the battery has a false "surface charge" that will give a high reading. If you don't want to wait, then turn-on the head lights with the engine off for a bout 30 seconds, turn them off, and then measure the battery voltage.

Now, you shouldn't have to do this, as it's the dealer''s job, but I posted it just in case you want to get some data yourself to help in your discussions with the dealer. My experience has been that they do a more careful analysis if they believe the customer has some understanding of what's going on with the vehicle. Talk directly with the mechanic/technician who works on it, if possible.

FWIW I've been monitoring our new (build date 8/4/09) X5 35d's voltage after sitting overnight. And guess what, I have NEVER seen a voltage above 12.45v. Just now it was 12.33v. This is on a brand new 35d which is commonly driven 25-50mi (one way) into the nearest larger towns. But occasionally only 3-5mi (one way) to the local village.

By way of comparison, there's the voltage on our ranch truck today -- 12.45v. The last time I drove it was about a week ago. OBTW the ranch truck is over 20 year's old, and is only RARELY driven during the summer (no AC and 105 degrees). A very busy week for the ranch truck would include a couple of 3-5 mi trips (one way). Many weeks it isn't driven at all. It hasn't seen a trip of 25 miles, or more, in months.

IMHO BMW is being disingenuous about the low voltage issue(s) on E70s. The "you don't drive it enough" story is simply a dealer excuse for a fairly serious design/implementation flaw on these overly complicated electronic juice hogs.:yikes:

Funf Dreisig

thanks for your help so far, yeah i know the dealer is trying to shy away from the problem. i just tested the battery after a long drive. it was 12.2. Has anyone had a dealer fix this problem ? if so what did they do ?

12.2 after a long drive tells me there is a problem with the battery or the charging system. A useful piece of information would be the voltage while driving, which can be measured from the power outlet in the console.

I'm taking mine in next week... however I don't hold out much hope.... I am reporting the high current drain message issue rather than a flat battery .. see if that gets me anywhere .. I was working on the car for around 2 hours one day and the whole system reset .. idrive would not power up as a battery conservation feature... I'm also hoping to get the peeling steering wheel fixed... :p:

One of the things I've noticed about the E70 is that some stuff never completely turns off if the key is in the 'ignition switch' and several things stay 'active' even when the key is not in the switch. Note: I don't have comfort.

For example,
When the key is in the 'ignition switch' you can't turn off...
* the audio system - you can mute it but it is still on displaying the station, RDS info., track info, etc.
* the i drive screen - you can make it very gray but not completely black (i.e. off)

When the key is not in the 'ignition switch'....
* any USB device in the center console is still powered up (i.e. the LED light is on).
* the CD changer's LED lights are on when you open the glove compartment,
* there is a high pitch whine in the engine compartment when you open the hood. It gets more quite after a short time
* if you have NAV you can hear the changer loading data as soon as you open a door.

Now add these 'resting' loads to the niceties of welcome lighting (even in broad daylight), floor lighting, powered tail gates, etc. and you've drawn a lot of power out of the battery even before it has to crank the engine. If you then only drive a short distance, the alternator doesn't make up the loss before you start the process all over again.

I still think this is a fundamental design/implementation flaw where BMW tried to do too much (instant gratification) with too little (alternator/battery).

Funf Dreisig

Yup.


Simple solution -- higher output alternator.


I wonder when the stubborn Germans will get around to it?

My Guess is not anytime soon Since BMW is very proud of this system :(

"Make use of every Watt: by charging the battery only when your BMW is braking, coasting or decelerating, Brake Energy Regeneration improves fuel efficiency by up to three percent and ensures that the full power of your engine is available for acceleration.

Today's vehicles require much more electrical energy than older models, due to the much wider array of electric and electronic on-board comfort and safety systems. This energy is created by the generator (also known as the alternator) which converts the engine's power output into electricity. In conventional systems, the generator is permanently driven by a belt connected to the engine.
BMW's Brake Energy Regeneration operates differently: the generator is activated only when you take your foot from the accelerator or apply the brake. The kinetic energy that would otherwise go to waste is now used efficiently, converted into electricity by the generator and stored in the battery.
Producing electricity in this highly efficient way delivers an additional advantage: when you apply the accelerator, the generator is deactivated - so the full power of the engine can be directed to the drive wheels. Brake Energy Regeneration thus increases fuel efficiency while simultaneously enhancing driving dynamics. As a safety precaution, the Brake Energy Regeneration system monitors the level of battery charge and will, if necessary, continue to charge the battery even during acceleration to prevent a complete discharging of the battery."

My question is just how low does the battery need to go before the alternator runs all the time?

Funf Dreisig

edit: to emphasize the key point

what should the voltage be whilst driving ? 14v ?

JamesBoags - i have mine booked in as well. I will let you know how i get on.