Aircheese

Battery being drained. 1.8A idle current when car stop. causes?

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My car is IS250 2006

I found my car Battery flatten on a weeks ago. After charged, I monitored the Battery voltage everyday. It kept draining all the time.

Today I just got a multimeter with 10 A current measurement capability.

I measured the current in idle, car locked, all switch off, including my dashcam. Still got a idle current at 1.8A. which is reasonable for my estimation per voltage drop. I believe this is also the correct number during nights.

I have check 4 out of 5 fuse box. pull out then plug in to see if the current changed. But not them.

2 out of 3 in engine room and 2 out of 2 in carbin. I wasnt able to located the box2 in engine room untill i got back home and check the manual. will test it tomorrow.

image.thumb.png.9aed0cb8a2d815f5dd5c5064a150939e.png

 

below is the schematic for box 2. they are more for lights

image.thumb.png.1c58a0baef1ae4b4b91a5fd196e1ed78.png

The Battery is fine, i believe there is no issue with Battery (tested charging/idle voltage and current, and i use the current to estimate its capabity, not seeing any issue.)

Have anyone dignois similar issues like the one i am facing? any experienece will help.

Thanks,

 

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If the car is 'asleep' and you're measuring a current draw of 1.8A then I'm afraid to say that you have indeed got a big problem - it should be somewhere in the region of about 35 to 50mA, perhaps slightly more.

I think the best thing you can do to start with is to watch this video:

 

 

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Note, make sure the key fob is well away from car ( not in your pocket) as if it is still in range then it will be activating the comfort access entry system and this will have a current draw!

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Sorry Texas, I replied to you but when I re-read your post my reply didn't make sense, but I don't know how to delete posts as the system only seems to let us edit them (unless I'm missing something), which is why I'm now leaving this message :wacko:

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Yes I feel your pain! I have that prob before and asked Mods for advice but to no avail!

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Thanks for your reply.

It kept raining here in Southampton. I only got a chance to test an hour ago.


It turns out the problem is on my dashcam voltage converter plugging on OBD port, taking additional 0.1A more on top of the "asleep" current 0.15A (door close, car unlocked). Both together drain a 0.25A in total.

My 70Ah Battery can only last 280 hours at that current. But I have not started my car for 2 weeks, 336hours, more than enough for the Battery to be flatten.


The current measurement I did yesterday was wrong because I have to open my car's door to do the fuse test. When doors opened, the car will take around 1.9 ~ 2.4A.

The current will drop in many steps during 20-30seconds after closing the doors. Will finally reach 0.15A.


I think 0.15A is acceptable now, even it is still larger than what Herbie mentioned 30-50mA. as long as it isnt 1.8A which could burn my car...

I didnt test the current in fully asleep mode(car locked). But i will measure the voltage every day for a week to see if the voltage is still dropping too much.

 

1 min video to shows the current change while opening/closing the door

https://photos.app.goo.gl/NKWuAXiqKvdfR21L8

 

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9 hours ago, Texas said:

Note, make sure the key fob is well away from car ( not in your pocket) as if it is still in range then it will be activating the comfort access entry system and this will have a current draw!

possible. I will test without the key around next time

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9 hours ago, Herbie said:

Sorry Texas, I replied to you but when I re-read your post my reply didn't make sense, but I don't know how to delete posts as the system only seems to let us edit them (unless I'm missing something), which is why I'm now leaving this message :wacko:

Correct, you can't delete, only edit.

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2 hours ago, Aircheese said:

I think 0.15A is acceptable now, even it is still larger than what Herbie mentioned 30-50mA. as long as it isnt 1.8A which could burn my car...

It isn't really, but 50mA is for when everything is in a low power state, which can take 10 minutes after the ignition is turned off and the vehicle locked.

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1 hour ago, ColinBarber said:

It isn't really, but 50mA is for when everything is in a low power state, which can take 10 minutes after the ignition is turned off and the vehicle locked.

Good to know. I might wait for 10 min next time.

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