Battery is in the luggage compartment. Raise the floor mat. Undo the screw of the right side panel. You have now access to the fuses and the battery. (Well, at least for an european 525i, but I haven't seen any exception in the manual).


Edit: Sorry 53r Sport. Didn't see your much better explanation...

 

Of course it will die! One thing is that the car tries to preserve energy, and it's true that ALMOST ALL systems will be shut down (legally prescribed systems like hazard warning lights and side lights are never disconnected), but even with this, the battery level can drop and it will not be able to supply enough energy to make the engine start. (Battery can be defective or reached its end of life).

It may even occurs that the car sent a warning measure during the night, but nobody was there to see it...



I received this message some days ago, when I was using a electric inflator connected to the lighter.

 

umm, wait, are you saying car batteries dont just die?

 

Here's a link to an older post that should explain how the car handles electical power issues, etc.

http://forums.e60.net/index.php?s=&sho...st&p=118669

 

IF the battery is defective, then YES, but only then.
All the systems that will NOT be shut down don't use enough power to drain the battery to a level where you're not able to start the engine, since evereything else will be shut down waaaay earlier.

 

Defective battery is probably the case - I can't understand how someone who drives 200 miles with a presumably functioning alternator can then have a working 80/90 Ah battery drained the morning after!

 

There are a lot of parts that can suddenly start to malfunction and drain the battery.

 

Under normal conditions, the only things that could possibly drain the battery below the amount needed to start the car are things classified as "legally prescribed auxiliary consumers." For example, if you leave the parking lights or hazard flashers on, they will stay on until the battery dies -- they will not be shut off by any intelligent battery charge monitoring systems.

 

Those "legally prescribed auxiliary consumers" are switched on by the driver, so he knows about. They don't need much power, what means it takes HOURS to drain the battery to a level an engine start is not possible anymore.

 

Here is new Service Bulletin related to this issue. May not be the case here, but is relevant.

SI B 61 07 06
General Electrical Systems August 2006
Technical Service

SUBJECT
No Crank, No Start, CAS FC A111

MODEL
E90/E91 (3 Series), E60/E61 (5 Series), E63/E64 (6 Series)

SITUATION
The engine does not crank. Only the SRS (Supplemental Restraint System) and red brake lights show in the instrument cluster with ignition on. FC A111 (ELV voltage supply fault) is stored in the CAS (Car Access System)

CAUSE
Low 15WUP signal voltage caused by faulty IBS (Intelligent Battery Sensor)

CORRECTION
In case of customer complaint, disconnect the IBS connector X13895 (3-pin connector with 2 wires). The IBS is located on the negative battery terminal. Follow the white/blue and gray wires from the IBS to locate X13895.

If the vehicle now starts, the IBS is faulty and must be replaced.

PARTS INFORMATION
Part Number
Description
Quantity

Refer to EPC
Negative battery cable with integrated IBS
1

WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.

Defect Code
Refer to KSD

Labor Operation:
Refer to KSD

Labor Allowance:
Refer to KSD