Battery Drain

Nilz

Defo worth the wait :)
Afternoon all :)

Didnt use the car all weekend and went to start it this morning and it didnt start!!

Managed to bump it on the drive and it started up eventually. Got to work and called the AA out, they said the battery was fine, but noticed there was a 0.4amp drain on the battery, we checked all lights internally and externally and couldnt find anything that would be causing this.

I have had a new aftermarket stereo fitted, but that would have been about 4 or 5 months ago now, so doubt it could be that....or could it?

Any ideas at all??

Cheers
Nilz
 

thegoal007

Another S3 owner....
sounds like it's time to start removing fuses to isolate where the draw is coming from. I know it wont be completely zero because of the clock and possibly the fan if you have just checked the battery after the car was hot (i'm guessing there). Alos make sure the rear interior light is not staying on, I missed that last time it happened to me after loading the rear with junk to take to the skip and the seats were down I must have accidentally set it on. Also I presume when the engine is running and have a lot of electrical things switched on (headlights, air con, stereo, interior lights) you are still powering the battery at around the 14amps (I think) - check with multimeter.

btw, i didn't think it was advisable to bump start these cars? not sure what the current draw is on the battery as standard.
 

Nilz

Defo worth the wait :)
Yes, may have to go down the fuse removal route, the last time i had a battery drain it turned out to be the alternator and the drain for that was 1amp +, so pretty sure its not that, we let the car cool down and left it for about 10 mins and checked and the drain was still the same, we checked all lights, interior, boot and glove box and all of them were off. Also checked the battery when the car was on and reading was fine on that too. (14.4V) i believe it was.
 

Bolly

Registered User
Nilz
I think it could be the stereo. I have the same problem with my car and I am looking for a solution (see ICE section - will post link in a moment).
Remove the fuse and check the voltage. You may not have noticed in the past few months because the alternator has been charging the battery back up. Question - is this the longest the car has been uun-used since installing the stereo?
 

Nilz

Defo worth the wait :)
OK cheers dude, my cousin actually connected the stereo up for me and it has dab and bluetooth, so not sure if its something there that is causing the drain. Im pretty sure he connected it to the interior light in the ashtray, if i recall correctly...I will check and come back to you.

I have left it longer over the Xmas break and it was ok, however as you say its been charging as its just being left overnight and then back on again in the morning.

Do you know which fuse it is by any chance @Bolly ??
 

Nilz

Defo worth the wait :)
@<tuffty/> Any ideas dude??

I saw you had an issue a while ago with yours, did you manage to get it sorted?

Also spoke to my cousin and he got the feed from the heated seat power, which is only powered when the car is on.....
 
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Bolly

Registered User
Fuse number 30 from memory, but i really could be making it up.

There is a list on the inside of the cover and it tell you which one it is. It is three quarters of the way down on the first column on the left as you look at it straight on. I think it a 5amp fuse (blue).

If the live was taken from the heated seats, then I don't think this is the answer, unless a live is within the wiring loom before the wiring harness for the HU - therefore you have two lives going in??? can that be so? Sorry I can't help.
 

<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
@<tuffty/> Any ideas dude??

I saw you had an issue a while ago with yours, did you manage to get it sorted?

Also spoke to my cousin and he got the feed from the heated seat power, which is only powered when the car is on.....

Connected to the s-kont fuse... can't remember the number off hand.... also removed the USB drive that I had in it all the time

Not sure which one thing fixed the issue tbh but it sorted it all the same

<tuffty/>
 

Nilz

Defo worth the wait :)
So do you think it's better to have it connected to the s cont, I think it's fuse number 37 rather than the heated seats fuse?
 

<tuffty/>

Badger 5 Edition...Its all about the flow...
Staff member
Moderator
So do you think it's better to have it connected to the s cont, I think it's fuse number 37 rather than the heated seats fuse?

Yes

<tuffty/>
 

Nilz

Defo worth the wait :)
OK cool will have a go tomorrow if we get a chance and see if we can leak test and find what's causing this and also move the connection to fuse 37 instead.

Thanks for the help so far @Bolly and @<tuffty/>
 

Nilz

Defo worth the wait :)
Quick update on this, had the amp clamp on the car and disconnected the stereo, this didn't make any difference so we tried various fuses and identified the heated door locks to be causing the drain.

Disconnected the fuse (17) and the ampage dropped to 0.18 from 0.40 which is apparently acceptable, so will see how this goes and if it cures the issue.

I'm hoping it is this....however would be good to know why this is happening and how to sort it out.

@Bolly
@<tuffty/>
 
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