Recently, I have had a battery drain problem where the car will be completely dead when I go to start it in the morning if it has not been driven for >9 hours or so.
I took it to the dealer who could find nothing wrong with the car and left it over the weekend. They had no problem starting it up.

It turns out that I normally keep a bluetooth-enabled SE T610 in the car, turned on at all times, but did not leave the phone with the dealer. I mentioned this to the Service Manager as the only thing I could think of that was different between what I normally do and what they did.

He talked to the tech working on the car, who is knowledgeable about the way the BT system works in the E60 and he said that leaving the phone on when the car is turned off would definitely keep the car from going to sleep, and eventually would drain the battery.

Has anyone else experienced this?

This is also a warning to other BT users, not to leave your phone on and in the car overnight. After three weeks with a new battery, this would drain it flat in 9-10 hours.

 

I'm glad to hear they seem to have resolved your battery drain issue! Have you had a chance to test it by taking the phone out of the car at night to see if the battery drain stops? Or I guess the dealer did not have the drain issue since the phone was with you. Good tip for those w/ BT!

 

Glad see you have resolve your problem. .. but I am thinking how this can be possible.

Soon as I turn off my engine, my phone status shows bluetooth disconnected..
Is that means that bluetooth is disabled???

Or is this depends on phone?

 

Not sure. But the tech who worked on it said that this would prevent the car from going to sleep. I've since gotten the car back, left it overnight with the phone turned off, and had it start up just fine in the morning. So that was the problem.

Not sure whether it's phone dependant or not. I assume if bluetooth is left on in the phone, it continuously "pings" to find a pairing and this is what keeps the car from fully going to sleep. My T610 has a "power save mode" for the BT handsfree. At some point, I may experiment to find whether that solves the problem.

 

I have a SE T637 and have left the phone on in my car overnight many times. Never once had an issue. When I turn off my ignition, my phone indicates that the BT connection has been lost and then goes into a sleep mode. Is it possible that it may be your phone settings?

 

Could be. It's also an old T610 with old firmware so it may be causing the problem.

The only setting I can see in the phone which could make a difference is in the Handsfree Options menu under bluetooth. There are two choices: Always On and Powersave. I've had it on Always On and was going to try Powersave to see if it makes a difference.

 

Could be. It's also an old T610 with old firmware so it may be causing the problem.

The only setting I can see in the phone which could make a difference is in the Handsfree Options menu under bluetooth. There are two choices: Always On and Powersave. I've had it on Always On and was going to try Powersave to see if it makes a difference.
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The only way I can think that could happen is if you were in the middle of a call when you shut your car off, I believe you can continue to talk until you disconnect the call. That being said, if your phone says Bluetooth connection lost, it can't possibly affect the vehicle and prevent it going to sleep. Do you have the snap in adaptor for the phone? If so was the phone left in the cradle when this happened?

 

One would think that would be true, but no. Apparantly just leaving the phone on with BT activated is enough to keep the car from going to sleep. That is what the tech thought and it turns out that having turned off my phone at night, the car is no longer suffering the battery change (nothing else was changed).

As the service guys said, the systems are complicated and can interact with each other in strange ways, which drive THEM crazy as well as us.

 

I have my V551 on in the car many times, no problem. As soon as I turn off the car, the phoe indicates that the BT connection was lost.

 

I think the tech is FOS. Especially since no one else seems to have that problem.