2002 E65 730D - battery/electrics issues maybe...?

[njw1]

Possibly your alternator could be on the way out as you should be getting about 14.5v with the engine at idle, also 12.3v is a bit low with the ignition off, a fully charged battery should read 12.5 to 12.6v.

[anonymous-user]

If the battery’s been down to 8v it could well be knackered.

[helix402]

The ibs logs closed circuit current drain so it’s a quick task to read the history of the amps being drawn.

A closed circuit current drain test doesn’t take too long, off the top of my head 30mA is a normal drain.

[helix402]

This may be helpful to you:

https://bimmerscan.com/bmw-intelligent-battery-sen...

The last E60 I fixed with a similar problem to yours was due to a faulty IBS sensor. You can unplug it to rule it out, guessing the E65 uses the same system.

[Elliot2000]

Have u got comfort access- the feature where u can unlock the doors by touching the exterior handles? If so, these used to be common for causin intermittent battery drain like u have described. U can disconnect them if ur not worried about the feature

[Elliot2000]

Yeh it definitely could be

[Prinny]

Parasitic drain on the battery from the door lock modules not going to sleep (they’re live for a long time - 25min or so IIRC) after locking the car is a known e65 foible. I’d be going with that based on what you’ve said so far. As to which one it is... could be any/all of them, not limited to your drivers one being wet, etc. (sorry).

This is a good starting point (pulling fuses).

https://www.bimmerfest.com/forums/showthread.php?t...

The other thing to check - seems odd, and the door modules are more likely - but how good is the battery in your key? That can cause the CA system to play silly buggers too.