Mbmw540i

So I recently purchased an 08 550 to replace my 07 550. I've had problems with the battery draining... The dealer has made two claims. One that my V1 detector is draining the battery even though its off. I have it hardwired the aux outlet on the passenger side. They claim I need to unplug it when the car is off. 2nd, they claim the new LCI cars need to be on a battery charger if left sitting for a week or longer. They claim this is a normal problem with the new LCI E60's...
I don't understand how a cars battery could drain after one week, especially a $75k car.
Any help would be appreciated.
Thanks,
Matt

triet545

I feel you, as my 05 545i is having the exact same issue but I do not have any add devices hooked to it. I've already been through my second battery and everytime I start it in the morning I get this high battery drain warning. If you find what the problem is please share. I will do the same.

Thx,

Triet545

Allen

If the V1 is turned off...then it will not be drawing any battery current. Also, on my car ('08 535i) the aux power plugs are not powered when the car is OFF...so anythng plugged into them can't draw any current when the car is OFF. Having said that...if your car regularly sits for a week or more at a time, you should get a battery tender on it. Your battery will last a whole lot longer and you car will be fully charged at all times. Since mine does a lot of just sitting these days...I just hardwired a battery tender to my car.

Rudy

Search these forums and you'll find much more information about this issue.

I'll try to summarize things here the best I can...

First, regardless of what the dealer says and contrary to many people's beliefs, it is not "normal" for these cars to need a battery tender! (Sure, maybe if the car is going to sit for a few months or more...but not for a few days!!)

The car, as everyone probably already knows, is quite complex and relies on many modules and software programs to function properly. These modules can drain a significant amount of power from the battery which is why the car is designed to go to "sleep" after it sits untouched for at least 16 minutes or longer.

In my opinion, based on my own experiences and based on my recollection of other people's experiences on the forum, the problem with increased battery drain we keep hearing about on many of these cars is likely due to the following conditions:
1) a device or module is not allowing the car to enter sleep mode
2) a device or module (or human interaction) that keeps repeatedly waking the car up from sleep mode without starting and/or driving off to recharge the battery
3) a marginal battery (which, when combined with the conditions above, can make things even worse)

Troubleshooting these conditions and tracing the problem back to its source can be quite difficult and, depending on the service technician's abilities, can result in either great success or terrible failure.

It seems that BMW, as well as many dealers, have resorted to claiming that there is an "unfavorable driving profile" that is causing the battery drain. This is a total cop out and clearly indicates that they're not able to figure out what's wrong and are giving up. Does an "unfavorable driving profile" ever exist? Of course! BMW has mentions two (somewhat vague) conditions that can cause an unfavorable driving profile:
1) driving "extremely short distances"
2) "excessively long periods out of use"

The vagueness comes from what defines "extreme" and "excessive". Clearly, we've seen dealers cling to this excuse by stretching (or shrinking) the definitions of these two terms.

On my LCI car, I've parked it for multiple weeks and when I returned to start it, it behaved perfectly. That said, I've had my dealer replace a few modules early on that were not letting the car sleep properly so I've seen the problem from the other side as well. (Keep in mind that my car is maxxed out with every available electrical option so if my car can do it, so can everyone else's...)

I don't know what else to say about this except to maybe add that if your dealer is bailing on you, see if there's another one that might be more willing to accept the fact that something is wrong. Also, depending on where you are in the world, getting BMW involved directly (like calling BMW NA) may at least allow you to get them to agree that something is wrong with the car and it's not "operator error"...

Mbmw540i

Thanks everyone, especially Rudy for the explanation. I agree, I should have to charge my battery when idle for only one week. Unfortunately, when my car came off the truck from TX, the battery was drained. I suspect the transporter didn't completely turn the car off (it has comfort access) and killed the battery. So I think my problem is a weak battery and there blaming the V1 as the problem. The V1 shuts off with the car, so I agree, but they claim the V1 is keeping the car from going into sleep mode. But lots of members here use the V1 and wire it to the same wires, so I don't see how that could be the problem. I live in NJ, in fact I used to live in Woodcliff Lake, which is where BMW of NA is. So I think I'll have to contact them next.

Rudy

I assume you mean "shouldn't" in your second sentence...

As far as the transporter you're referring to, are you talking about when the car was delivered new or was it some time afterwards? By the way, even though I've seen many people point to comfort access as another source of the problem, I don't buy it. By design, you should be able to leave the keys in the car or even just outside the car and it will still sleep properly and will not cause undue battery drain. In other words, cars with comfort access should not cause any additional battery drain than cars without CA!

The following two documents in the technical gallery will give you more than enough information about some of this stuff:

Comfort Access:
https://5series.net/forums/index.php...mage&img=10674

E60 Power Supply:
https://5series.net/forums/index.php...mage&img=10935

Mbmw540i

I bought the car used, had it shipped up from TX to NJ. What I meant with comfort access is you have to press the button twice to turn it off. If you only press it once, the radio, etc. stay on. So I'm thinking maybe that drained the battery dead during transport and he jumped it before delivering it. I looked at the service history before I bought it, and there's no record of battery issues and the guy before had his Passport hardwired to the same power supply. Thanks for the links, I'll check them out and them scream at the dealer :-)

Gilgorm

I agree with everyone about BMW claiming we don't drive enough, although my dealer has never suggested that to me and worked diligently to find my 'high battery discharge' issue. Week 1-replaced main comfort access module(not the door handles); week 2-replaced LCI electronic gear shift module; week 3-hunted down then removed 'boomerang' after discovering previous owner had an anti-theft system that had never been shut off. My car now sits for days at a time with no problems----knock wood.

bigbadbull

I though there was a TSB recently instructing the dealers to replace the batt's with the new style Lead batts.

There were issues with the Plates coming loose in the batts., or some thing similar.I might have seen this in a 3 forum , but I know there is some thing recent on it.

Rudy

I recall something like that too but that's not a fix for the battery drain issues we're talking about, that's just a band-aid that might buy someone a little extra time between dead batteries...