2005 525DSE Auto

Another battery drain story ....

First off I've had no problems with battery drain before. I used the car Saturday morning and garaged it at about 13:00 - 13:30. On Sunday (roughly around the same time) while sitting in the lounge, I heard what I thought at first was a distant house alarm going off. It went off and on several times. It sounded like a truck reverse warning. Then I though it might be a car alarm. Sure enough the alarm was sounding on my car in the garage. I grabbed the keys, went in to the garage and pressed the 'open' button on the fob. Nothing happened. The alarm started again. I then opened the drivers door with the key and the alarm stopped. No interior lights came on. I looked around the car and the near side front fog light was on (very dimly lit). I popped the boot lid with the key, got to the battery and attached a battery charger. After doing so the fog light went out. The lights were on '0' and no fog light buttons were pressed. I then pressed the key fob and the indicator lights flashed. The inital charge rate on the battery charger had the needle fully defected > 6 amps. I left it charging until 10:00pm when it was showing about 3 amps. I left the doors unlocked.

I put it back on charge the following day (Monday) and took it off charge about 6 hours later (14:00) when it was showing 2.5 amps. I got in and entered the 'secret' menu, item 9, this was showing 12.6 volts. As I started the car this rose to 14.8 volts. Took it for a bout a 4 mile drive and returned it to the garage. Locked and alrmed the car with the fob.

On the Tuesday before I drove 35 miles to work I entered the 'secret' again and it was showing 12.6 volts. As I started the car this rose to 14.8 volts and remained flickering between 14.4 and 14.8 all the way to work. At work I closed 3 out of 4 doors manually (in a secure underground works car park) and when I came back at night I used the 'open' on the key fob and the interior lights came on and the 3 door locks popped up. Checked the volts, 12.6, drove it home (14.4 - 14.8 volts once running). Parked it in the garage and used the key fob to lock it and set the alarm. Started my stop watch. Went out to the garage after 15 minutes ... waiting for the 16 mintues when the orange light next to the gear lever would go out. 16 mins came and went, as did 17, as did 18. Went back inside the house. Came out again after 29 mins and after 30 mins the light went out and there was some sort of click from the rear (where the battery is). This was at 18:30.

Worked at home today, went to the car at 14:00. Opened the car, entered the 'secret' menu and it was showing 12.6 volts. Locked the car again, indicators flashed, red alarm light on, orange light on near gear stick. Went out after 15 mins for the 16 mins timer, orange light still on, went out after 29 mins and again after 30 mins light went out and small noise from boot area.

I've not had any messages on the iDrive.

As the battery now seems to be holding at 12.6 volts this seems to indicate the battery is OK ('green' in the 'spy' window) and once the car is started its shows 14.x volts, this seems to be indicating that the alternator is charging the battery correctly.

I've searched the forums (hedgehog etc) but not come across anything where 1 front fog light has come on and the alarm is sounding and the car won't respond to the key fob and the battery is drained.

Questions:
(1) Anyone come across this particular combination of events or ideas what caused it?
(2) Is 30 mins normal for a 525DSE to enter 'sleep mode'?
(3) I do normally have a radar detector plugged in to the lighter socket (switched off via its power button) - could just having it plugged in stopped the car going in to sleep mode (and why now)?
(4) Could it be a one-off mystery (hope so)?

thanks.

I had a faulty rear door control unit that caused some problems, high battery drain, active steering fault and on one occasion had the windows all open during the night. The problem disappeared after the faulty control unit was located and replaced under warrantee. The Radar detector should not cause a battery drain, as the power unit is switched to prevent power loss while the car is off. I'm not certain what the timing for the sleep cycle is, I think it is 20 minutes to sleep on North American E60's.... I hope you don't have any repeats and can log this into the odd and unexplained category

Another one! Take a look at :-

https://5series.net/forums/index.php?showto...p;#entry1057288

romansg - I too hope I "can log this into the odd and unexplained category"

tooltec - Read that and keeping my eye on any out come (BTW I see you are from my neck of the woods)

Any one with an E60 (particularly a 525D) who has time - can you test how long it takes for your auto orange light to go out - thanks

I can't give you a definite time for our E60's other than to say between 15 and 30 minutes.(I'm in the south of the county near to the Derbyshire border.)