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Has anyone confirmed that there is more battery drain by NOT locking your car yet shutting down all accessories vs double locking and having the alarm draining the battery..
I never lock mine in the garage.
Heck most times I leave the key sitting on the car.
My recent experiment, which started at 12.4x
No Ctek, drove 5hrs. Parked in garage, didn’t lock or check voltage.
24hrs sitting, 12.57v (charged during the drive.
Just went out, sitting 48hrs, unlocked and I turn it off without turning off radio, AC or any of that.
12.49v.
Will be driving it maybe 5mi this evening, but will check tomorrow.
If it drops more, I’ll hook up the Ctek.
I never lock mine in the garage.
Heck most times I leave the key sitting on the car.
My recent experiment, which started at 12.4x
No Ctek, drove 5hrs. Parked in garage, didn’t lock or check voltage.
24hrs sitting, 12.57v (charged during the drive.
Just went out, sitting 48hrs, unlocked and I turn it off without turning off radio, AC or any of that.
12.49v.
Will be driving it maybe 5mi this evening, but will check tomorrow.
If it drops more, I’ll hook up the Ctek.
I thought that leaving key in the car keeps the accesories hot and drains system?
Looking fir definitive proof that the alarm doesn't drain more than not locking car..
Circumnavigator seems to have found no effects of leaving keys in car AND not locking?
I didn’t say no effects. It dropped from 12.57v to 12.49v in the second 24hrs of sitting.
Top down. Key fob sitting on the flat surface behind the psgr door.
Opened the trunk twice, but with LEDs in there doubt it drew much.
I am actually shocked having seen many threads about the alarm system, nobody measured the standard current draw for the alarm when operating as designed with no short or issues.
I’ll now be spending the next 10m reading the doc Sean shared, but on page 1 I found this comical: Close/latch all doors. But measure at battery. Which requires the trunk to be open, especially on a convertible.
Yes I realize it is directed at mechanics who have SDD.
But for a multimeter, this is impossible:
Last edited by Circumnavigator; Oct 21, 2025 at 06:34 PM.
I didn’t say no effects. It dropped from 12.57v to 12.49v in the second 24hrs of sitting.
Top down. Key fob sitting on the flat surface behind the psgr door.
Opened the trunk twice, but with LEDs in there doubt it drew much.
I am actually shocked having seen many threads about the alarm system, nobody measured the standard current draw for the alarm when operating as designed with no short or issues.
I’ll now be spending the next 10m reading the doc Sean shared, but on page 1 I found this comical: Close/latch all doors. But measure at battery. Which requires the trunk to be open, especially on a convertible.
Yes I realize it is directed at mechanics who have SDD.
But for a multimeter, this is impossible:
Does not activating and not locking the car actually cause more battery drain?
:-) have a read of the workshop manual. The car will automatically shut down after a period of time. It can be as long as 20 minutes.
short answer: no.
incidentally, you are not alone and you’re thinking. In the beginning days, there was a lot of conversation about the electronics.
I didn’t say no effects. It dropped from 12.57v to 12.49v in the second 24hrs of sitting.
Top down. Key fob sitting on the flat surface behind the psgr door.
Opened the trunk twice, but with LEDs in there doubt it drew much.
I am actually shocked having seen many threads about the alarm system, nobody measured the standard current draw for the alarm when operating as designed with no short or issues.
I’ll now be spending the next 10m reading the doc Sean shared, but on page 1 I found this comical: Close/latch all doors. But measure at battery. Which requires the trunk to be open, especially on a convertible.
Yes I realize it is directed at mechanics who have SDD.
But for a multimeter, this is impossible:
Ok, so it’s not telling you how to fool the car into thinking the trunk/boot is closed and latched, or how to run longer leads to the meter outside the trunk/boot, and close the lid on them? Easy enough to do either one, not rocket science.
Ok, so it’s not telling you how to fool the car into thinking the trunk/boot is closed and latched, or how to run longer leads to the meter outside the trunk/boot, and close the lid on them? Easy enough to do either one, not rocket science.
yep, also, open the door and physically close the latch while leaving it open. then press the lock button on the FOB. you've tricked you car into thinking the door is closed. Though I've never done this on the boot, I do it all the time when cleaning my interior. Easiest way to see that it's working after to physically close the latch with a flathead screwdriver. When you press the lock on your FOB, the dome light goes off immediately. That or just get longer leads as @kj07xk noted.
yep, also, open the door and physically close the latch while leaving it open. then press the lock button on the FOB. you've tricked you car into thinking the door is closed. Though I've never done this on the boot, I do it all the time when cleaning my interior. Easiest way to see that it's working after to physically close the latch with a flathead screwdriver. When you press the lock on your FOB, the dome light goes off immediately. That or just get longer leads as @kj07xk noted.
I was just nit-picking.
I’ve done it for the boot while I was hard wiring the Ctek and messing about.
Doing the doors just never crossed my mind.
Will test on t after my 3 days sitting battery measurement.
I was just nit-picking.
I’ve done it for the boot while I was hard wiring the Ctek and messing about.
Doing the doors just never crossed my mind.
Will test on t after my 3 days sitting battery measurement.
Surprised you haven't done a test after double locking , to see what difference it makes..
US members who "double lock" their X150 will get a "beep beep" from the sounder. That double beep is an error message that means your car is not double locked. That's because double locking is not available on US market cars.
Double locking is not available on USA market vehicles because NHTSA deemed it to be unsafe. Double locking is popular in Europe because it makes cars more difficult to steal. However, because the doors cannot be opened from the inside when double-locked, a small child or other passenger can be trapped inside and die from extreme heat.
When you double-lock your car, the beep-beep is an error message to tell you that your car is not double-locked. Visual confirmation that your car is, in fact, locked is that your side mirrors automatically folded in, unless you disabled that feature or your car is not equipped with that feature.
US members who "double lock" their X150 will get a "beep beep" from the sounder. That double beep is an error message that means your car is not double locked. That's because double locking is not available on US market cars.
Double locking is not available on USA market vehicles because NHTSA deemed it to be unsafe. Double locking is popular in Europe because it makes cars more difficult to steal. However, because the doors cannot be opened from the inside when double-locked, a small child or other passenger can be trapped inside and die from extreme heat.
When you double-lock your car, the beep-beep is an error message to tell you that your car is not double-locked. Visual confirmation that your car is, in fact, locked is that your side mirrors automatically folded in, unless you disabled that feature or your car is not equipped with that feature.
