Drain on Battery

beanoir

beanoir

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Ok, i've had a search but not really found too much, so thought i'd ask the question.

Ive got a parasitic drain on my battery and this morning it was as dead as a black gospel singer with a crack addiction. Had the RAC dude out to juice it (as I couldn't get it up on the drive by pushing) and he tested the battery and the alternator and he said it's charging fine but that something is draining about 0.5amps from the battery when the ignition is off which is way too much (should be about 0.05amps).

I've checked all the bits i've found from searching, boot light staying on, glovebox light etc etc. The only thing I can think of is the new head unit i've installed, but i've got the live feeds correct as far as I can see, so i'm kind of at a loss - unsure if the amp has any funny connections I should be aware of that might mean it's not turning off (although i've got it connected to the remote). The battery is charging overnight so I can start testing all the circuits one by one with a multimeter tomorrow.

So if anybody has any pointers before I trial and error then i'd be grateful!

Cheers
 
Hi Buddy ,
Just read your post ref parrasitic drain . When i first bought my 02 Plate S3 i had exactly the same problem , battery kept draining down within 48 hours . Turned out to be a parasitic drain from the OE head unit , pulled the fuse and hey presto no more drain .
Ended up changing the head unit for a good second hand one , problem solved .

Cheers Ant
 
did he test it just after stopping the car ???? as there is a pump that runs on for 10 mins ish after car is stopped
 
Thought i'd pull this thread back up as i'm still having the same problem with the battery draining. A couple of weeks ago I went through the entire process of checking each circuit by pulling the fuses and using a multi meter. It turns out (as Fingermouse rightly points out) that I wasn't leaving the car long enough for all the systems to shut down (although I did unplug the aux water pump but there are others) and so my readings were all wrong and falsely diagnosed it as my new head unit.

Anyway, after replacing said HU with a new one, I was still getting a dead battery after a couple of days of not using the car. So today, I fixed up a multimeter, locked the car and left it for an hour. Went back and the reading on the meter is 0.01 which is fine, so now I am really at a loss as to what the hell is making my battery flat as there clearly isn't anything draining the battery, and the RAC guy said that the battery and alternator were fine (on 2 different occasions)

Could this be a earth related problem?
 
Mine will go flat if I don`t drive it for say 2 weeks. But I sometimes move it in and out of the garage to get to stuff then I know I need to charge it or it will let me down. Ive had 2 new batteries on it (one under warrenty) and it seems to solve the problem but only for a year or 2.

I just put mine down to the amount of miles I do and possibly draining the battery with relativly short runs of say 15 miles to and from work with all the bells and whistles on.
 
Well mine doesn't get regular journeys either and any during the week and any it does do are just around town. But then that's all I ever do in any of my cars and I've never had a problem with batteries.

Anyway, I bit the bullet today and ordered a Varta Silver hoping that gives a bit more oomph to it as the battery is looking a bit old and not a premium looking unit either so fingers crossed!
 
not all cars have all the lights and stuff that the S3 does, there is a hell of a drain and with the pump running on Im guessing your suffering a bit like I do but a new battery is always worth it :) piece of mind and hopefully solves the issue
 
if it really is only drawing 0.01A, then the next step would be to disconnect the battery from the car for a few days, and see if it still drains. If so its a knackered battery.
 
we have this problem aswell we done all above disconnected the battery and yes it went flat after 2 days had a new battery fitted but that went flat after 2 days on the car aswell i been told there is no drain and the charging system working fine so i aint got a clue whats killing the battery anyone have any idears what i can do to locate whats killing it thank you
 
same thing here dunno whats killing the battery ATM, local audi indy recons the sounder for the alarm can cuase problems but I need to find it!
 
Mr Fixit said:
same thing here dunno whats killing the battery ATM, local audi indy recons the sounder for the alarm can cuase problems but I need to find it!
Click to expand...
It's in the boot behind passenger rear light
 
I had a big drain and it ended up being the heated door lock, there was a fuse for it,once we pulled that the car was fine...maybe it has stayed on during the cold weather.
 
so this is still proving a challenge, last night connected ammeter and removed each fuse in turn, nothing no change at all, even took out the relay and disconnected each of the large connectors over the battery still nothing. Next is a check on the alarm siren and repeat with new meter as I've had mine sine I went off shore blah blah years ago!.
The car had been sitting fro two days and started OK, drove to the stations (3 miles) no lights and the big OK on the dash. Park in at the station for approx 8 hours and battery dead. So it would seem to be something that is running post ignition off but after the car has been run/warmed.

This has all the hall marks of either a sticking relay or a warn motor/generator stopping with the warn brushes across the armature plates or similar.

More to follow
 
Another thing to check would be the fuse box under the bonnet, I had another drain a while ago and it was the alternator that was the issue, we checked it by putting an amp clamp on the fat black cable and that came up with a massive drain.
 
so I have found that there is a pump on the front of the car just above the secondary cooling fan that seems to run for a while after ignition off;- what is this.

In addition watching the meter I can see the load increase and then drop off when the car is lock, first to around 3 amps then to 1.6 ish and then to around 500 mA where is stayed varying between 500 and 300 mA. It also did different things based on the lock status (locked or unlocked). The local Indy is convinced its the alarm sounder as the batteries fail and then cause a drain constancy charging. He has go two wrists in each arm so is going have a look for me as I have snapped a bicep tendon and simply cant get my hand to work in the small space!
 
A little research reveals its the Auxiliary water pump and seems to be intermittent as well as noisy ;- could this be the source of the parasitic drain I wonder!!
 
unplug it if you are worried - it continues to circulate the coolant after the engine is off to look after the turbo - mine is weird it sounds half dead most of the time.
 
i had similar parasitic drain style symptoms, prev owner had put a new battery in 3 months before my ownership. replaced this with a bosch job and new alternator and its been fine since. i did replace the aux pump also around this time, so it may have been that that causing the issues. was also winter and infrequent short journeys.
 
Update;- Aux p[ump is OK and I think its teh head unit so replaced with a recon OEM unit to keep the right look. So far so good but still cranking a little slow but does start OK. Will put battery om charge to assist with recovery of the battery, take for a run and see what happens but my local Indy did a check (whilst fitting new rear bushes to the from wish bones) and confirmed the OEM head unit.

A thought on bad earth;-if you have a high resistance (bad earth) even a low drain will increase significant so worth redoing the main earth as well

Car also had 4 wheel tracking and is now sooo much better as one bush was worn !!
 
I had a mega drain which was caused by a fault in the radio /satnav unit. It was 3.87 amps, huge, so I pulled the fuse.
I then had a further drain from the alarm system, flat battery within three days. Overcome at the moment by connecting a 10 watt solar panel in the windscreen into the cigarette socket. It works well. Radio still not connected unless on a journey when fuse put back in. Don't want to spend money guessing.

However Phill Miller (MILLERS MOTORS) Launceston Audi Specialists , told me last week that a new magic wand is on its way, when passed over cables, components, and anything electrical, it will show any drain. Let's hope it works and we can go to THE problem without expensive guesswork. I will post results.
 
All seems sorted now, new OEM recon stereo fitted and seems fine, also worth noting that if you switch the car off with the Traffic Announcements on it stores that last few announcements and this does increase the draw as the stereo does not actually switch off!
 
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