[toot535ix]

I just got a 'replace battery' warning...my F10 is only 6 months old!
Has this happened to anyone else? Why would it occur?

[jdubbs]

Yes, it happened to me too, on my 550i GT. My dealer initially said it could be due to my not driving the car enough, but they took it in to do a full electrical diagnostic, and they discovered a problem in the electrical system... basically the car was drawing too much power. They upgraded the software overnight and the next day the Replace Battery warning went away.

If, like me, you don't drive your car a lot, you might also consider locking the car at night (fewer electrical systems on standby when the car is locked) and/or getting a trickle charger for the battery.

BTW, my car is also six months old, which suggests that perhaps there was a flaw in the software back when our cars were being built (Jan 2011 in my case). I wonder if others with similar build dates are also experiencing this?

[cc3]

This battery warning sign has just come up on my car. Going into dealer tomorrow. 10 months old and 9000 miles.

[EV0LVE]

i had the battery replaced within 6 months of owning the car, i'm so tired of figuring out the problems with this car.

[MHK]

Interestingly, I have a 6 month old 535d with low miles as well (delivered Jan 2011). This weekend, I received the same battery replacement error after plugging in my kids iPad to be charged in the rear socket. I just schedule service in London to have them pick up the car next week.

[tp550i]

I hope this is not an issue with the Brake Energy Regeneration since our cars do not have a conventional alternator. This technology has been used for years in hybrids.

from BMW:
To supply a battery with electrical energy, the generator (alternator) is usually driven using engine power, which requires fuel. With Brake Energy Regeneration, the generator produces electricity when the driver brakes or takes a foot off the accelerator. Kinetic energy that was previously unharnessed is transformed into electrical energy, then fed into the battery. In this way, electricity is generated without consuming fuel.

[LuvMyE92]

Originally Posted by tp550i

I hope this is not an issue with the Brake Energy Regeneration since our cars do not have a conventional alternator. This technology has been used for years in hybrids.

I think our cars do have an alternator. There is no brake energy regeneration, that's marketing hocus pocus. The alternator simply has a clutch in it that has it operating (unless that battery needs a big charge) only when the car is coasting or braking.

That's my theory anyway. If you want to prove me wrong, send me a picture of the generators attached to the wheels. Or the brakes. Or wherever you think it is. I think it's hanging off of the engine, driven by a belt.

[BMWrules7]

The problem could be a threshold issue with the vehicle monitoring system.

Engineers predict at what point the battery error message should be displayed.

This setting works fine in the lab. But, when the monitoring system is placed into production use a lot more factors, such as environment, low milage, high mileage, etc come into play that were not present during testing.

So, there may not really be a problem with the battery. These could just be phantom error messages. A software update expanding the monitor threshold parameters usually does the trick in this case.

[cc3]

My car has been in the dealer today. Fault is a software problem and they need to recode the car and need it for a day. So going back in next week. Dealer has seen problem before nothing wrong with battery the software problem just triggers the warning. This will be my second recode - cars are getting too complicated!

[radarguy]

Originally Posted by LuvMyE92

I think our cars do have an alternator. There is no brake energy regeneration, that's marketing hocus pocus. The alternator simply has a clutch in it that has it operating (unless that battery needs a big charge) only when the car is coasting or braking.

That's my theory anyway. If you want to prove me wrong, send me a picture of the generators attached to the wheels. Or the brakes. Or wherever you think it is. I think it's hanging off of the engine, driven by a belt.

You are correct it is marketing fluff. First time I've heard of such exaggeration from a car manufacturer.

[E90Fleet]

Originally Posted by radarguy

You are correct it is marketing fluff. First time I've heard of such exaggeration from a car manufacturer.

BMW nowhere says they use anything but a alternator that only connects when the car is coasting,braking or when the battery is too flat.

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

[cc3]

Dealer has now fitted a new battery to my 10 month old car after battery replacement warning came up

[MHK]

Mine goes in Tuesday for same issue in London. I spoke to the service department, they suspected it also might be a software issue. Will be interesting to see what they say. I did just drive 4 hours this morning for the holiday weekend, no issues other than the warning.

[chuds]

My Jan 2011 535d msport has the same prob at the mo, also traction light sometimes stays on and radio reception is rubbish. Booked into dealer next week, with only 4k under its belt its a bit crap for a 55k car!

[MHK]

got my car back from having the software upgraded. Fault is gone and no issues.

[toot535ix]

My go a software upgrade--no problems!

[EV0LVE]

I thing I noticed is that the ipod kept charging even after I shut off the car/engine/accesories, could this be the culprit? i cant imagine an ipod draining the battery though.

now, my car never ran out of battery power it just had an error message about the battery power being low.

[chuds]

Mine had a new battery and a download, faults now gone and back to normal.........for now!

[b535i]

I have been fighting this battery drain problem for 5 months on new 2011 535i. Dealer is saying it is my driving style typically few miles on short trips intersperse with longer drives. Car now has 10k miles. This is unacceptable.
Waiting on dealer analysis but previous dealer visits has not turned up a solution. Plugging in a battery tender each night is not an option...it is a waste of time.
Just joining this thread to note the experience...as the Audi ads say "more BMW owners are moving to Audi!"

[Hunter5179]

On the cars with battery drain issues how many of you guys have soft close doors and power trunk?

[Loni5z]

I had the car for 4 months and i had to replace my battery. Took only a second so i didnt mind at all.

[bamboozle]

My 550 around 8 months I started having issues with my car turning on. Dealer replced the battery but I never got a warning, almost left me stranded.