Dead battery....doors unlocked

A

AldridgeZ4

Member
 Walsall
I haven't used the zed for a few weeks and thought I'd hook up the Ctek overnight. The car was unlocked and the battery totally dead, so dead that the ctek wouldn't charge it. I'm sure that I locked the car and I check it every now and then so can't understand why it was unlocked. My overactive imagination is worried about some sort of theft attempt, but their isn't any signs of damage or forced entry. Would the doors automatically unlock as the battery is about to die?
The battery was from 2013, so I've bit the bullet and ordered a new one.
 
It shouldn't unlock with a low battery. You can open it manually with the key so no need for an auto unlock feature.
 
People have posted similar experiences over the years, several realised that they or someone with the other key had accidentally plipped a key in their pocket or bag etc. Leaving these cars unlocked also tends to run down the battery as systems don't go in to sleep mode.
 
Ewazix said:
Leaving these cars unlocked also tends to run down the battery as systems don't go in to sleep mode.
Click to expand...
Not according to what I measured when trying to track down a parasitic power draw issue. Regardless of the locked state of the car everything shuts down into sleep mode after a few minutes of being idle.
 
Interesting finding and contrary to the experience of several members with battery drain problems including a recent thread,
https://z4-forum.com/forum/viewtopic.php?f=3&t=111017&p=1612874

As a matter of interest how did you measure the draw when the car is shut down? I had a hell's own job working out how to measure drops in different states over fuses when tracing a drain, particularly since the alarm module(s) will not be set or the car shut down fully with the bonnet open? :|
 
[ref]Ewazix[/ref], I actually had an ammeter in series with the battery - after a few minutes the current drops right down to something like 45mA. The same as the target sleep current figure is specified in ISTA. Note that all doors were closed but not locked (the boot was open so I could see the meter but a screwdriver was placed into the latch so the car thought it was closed).

Rapid battery drain is caused by faulty electronics - control modules that don't sleep. In my case it was my Gaptech module intermittently keeping one of the other modules awake.
 
Mangozac said:
[ref]Ewazix[/ref], I actually had an ammeter in series with the battery - after a few minutes the current drops right down to something like 45mA. The same as the target sleep current figure is specified in ISTA. Note that all doors were closed but not locked (the boot was open so I could see the meter but a screwdriver was placed into the latch so the car thought it was closed).

Rapid battery drain is caused by faulty electronics - control modules that don't sleep. In my case it was my Gaptech module intermittently keeping one of the other modules awake.
Click to expand...

Crafty work :thumbsup:
 
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