vishwen

As i am having problem of my battery saying high rate of battery discharged,
Been to the dealer today , the technical manager told me that infact i did not drove the that much and have taken out a battery history , saying that the battery is only 50 % charged and he did recharged it , when i get back home after driving like about 50 km , switch off the car and after 6 hours and check the car it says same thing high rate of battery discharged. My question to the tech manager is that why the car is pumping power from the battery when the car goes to sleep mode , which means one of the car module is not going to sleep mode thus pumping juice from the battery , but he cannot find anything from the dianostic . He told me that to bring the car again and i will have to leave it overnight with him so that the next morning he can check it.By the way i do not have comfort access in my car . I personally do not think that the battery not fully charged can cause this problem what do you guys think ?

All the accessory i have added like: Amp , Radar , Rear socket for Cigar lighter , dension 500 and dvd i have disconnect all of them thinking that may be one of them may cause the battery drain.

Please help me guys.

Howitzer

I'm guessing its that JL sub and amp and TV and all that other stuff you added that contribute to this. I would suggest a stronger battery or at least 1 farad capacitor to run in-line with the positive on your amp.

vishwen

thks Howtizer , i had these accssories for long time , and did not have such problem , as i said i disconnect all these items.

billeul

I had been experiencing a similar situation with 2004 545i. My car was not going to sleep and discharging my battery. After two 30 day stays at the dealership, they came up with the same result both times. The dealer says that the TCU is damaged and not letting the car go to sleep. When the car is supposedly in the sleep mode, with the TCU connected they measure approximately twice the acceptable battery draw ( I believe 80 mA instead of 40 mA). With the TCU disconnected the battery draw is normal. They have replaced the TCU twice. I feel the dealer and BMW gave up on trying to discover what is damaging the TCU. Instead they told me that since my Blackberry 8830 is not on the compatible phone list, that by pairing it with my car the phone could be damaging the TCU. I was told that if I do pair the 8830 again and if the battery dies as a result of a damaged TCU, the TCU can not be replaced as a prexisting problem warrantied issue.

You might relay parts of my experience to your dealer. Please let us now what your dealer finds. Thanks

theXman

Connecting to a Blackberry 8830 should not damage the TCU. If that's the case, then everyone using late model blackberry or iPhone would be having the same problem. I seriously doubt that that is the truth. You dealer had no clue and decided to BS. You should continue to use the 8830, if and when it happens again, delete the phone profile and add in a new phone from the approved list, bring to the dealer and have them fixed it again.

vishwen

Well guys , thanks for the great Info .

As i can see a lot of people having same issue , but different solution .

Before changing the battery , today i will change the battery acid and put the battery on a 8amp charger and will see if get better tomorrow.

What other suggest you guys have?

vishwen

vishwen

HI Guys

i am still sitting with my problem still the same .

any ideas whether to change the battery or not.

Thanks Guys.

thedreamshop

I have the same problem on my car. The first thing I am checking is if the CAS module shuts down the power wires used for the display screen ( which also power the ACM ) when in sleep mode. Also are your cameras stock or aftermarket? Are the cameras connected to constant and trigger or ignition and trigger? I have disconnected both of my cameras ( stock ) and still have the drain and am going to investigate it more since the only thing left in my car is the Gateway 500 and the ACM. By the way, if you connect anything to ground it must not be directly on the battery terminal, you have to ground devises on the other side of the current sensor on the negative terminal, otherwise the computer is not aware of current going in or out of the battery on those wires. On the E39 there are a 4 or 5 well known things that cause battery drains and on our cars they are so new that we do not know what to expect as common battery drain causes yet.

gatemaster

Probably checked, but i have to ask,
The dealer checked your alternator output ?