Battery drain?

[Cornershop]

Gents,

The battery on my S8 has completely flattened a couple of times now in the space of 4 weeks. In between, I bought the AA solar conditioner, but forgot to plug it in, after its last use on Monday afternoon. :rolleyes:

This evening, it's completely flat - can't use the blipper, no lights on dash, no nuffink.

Somewhat coincidentally (I think) on both occasions, the car has been parked on a slight downward incline, perpendicular to the kerb, left side down. We live in purpose built flats with shared parking slots, so don't always get to park where I want, ie in front of the flat and on a level.

Probably nothing, but is there anything that could be left enabled, by parking on an incline ? I'm thinking of maybe the alarm module, is there a tilt sensor perhaps?

It's also entirely possible the battery was screwed after the first time, hence its failed again so soon, although I did leave attached to the the CTEK overnight.

Anything i can test via VCDS?

Cheers folks

[Delboy]

D2 or 3

[Cornershop]

D2

[Delboy]

Not familiar with them but there is a vw file I have on computer about checking voltage drop across fuses, attached for you

[ainarssems]

It's also entirely possible the battery was screwed after the first time, hence its failed again so soon, although I did leave attached to the the CTEK overnight

Yes this is entirely possible. If you run battery flat enough that it does not start the car it will damage it. If you run it flat enough that dash lights don't come on you will damage it a lot, if you leave it at this discharged state for week it will be pretty much unusable.

I did leave attached to the the CTEK overnightt

How many amps is your charger? 5 amp CTEK charger will take about 20hrs to charge good fully discharged 100Ah battery to 80% and then another 25-30hrs to get to 100%

There are no commonly known issues that will drain battery in D2, parking on incline should not affect it unless you have blocked plenum chamber drains, it could cause water to overflow in rain and leak onto electronics so parking on incline could be a factor if or where the water will come in. Only thing VCDS can check on D2 is voltage.

You could go to Halfords and ask them to check battery condition for you they normally do it free of charge.

You might also want to check residual drain current from battery with everything off.

Another possibility is poor ground or positive connection for for battery which could lead to less current going through and slowing the battery charging when running and giving less current when cranking. You can check this by comparing voltages measured directly on battery, battery + to ground and + at the front of car to ground.

[Cornershop]

Thanks both for your assistance.

I have the 5A Ctek and charged it to 80% as I had to drive the car the next day. I'll remove it tonight to give it a full recondition charge.

I've not checked the plenum drains since ive bought it but did clear the 2 wheel arch drain just after xmas. You could be onto something there as if there was any water in that area, it would drain towards the ECU etc the way i parked it.

I may call the RAC out to do a load test on the battery. If all is well, will attempt the residual drain test.

I've never known such a difficult battery to remove from a car, what a ridiculously sized compartment.

[HPsauce]

I've never known such a difficult battery to remove from a car, what a ridiculously sized compartment.Does your battery have handles, it should?
I've changed a D2 battery before and it wasn't difficult at all and I'm definitely NOT a mechanic.
Bit tight and the cables needed care to get out of the way but that's all.

[Cornershop]

Does your battery have handles, it should?
I've changed a D2 battery before and it wasn't difficult at all and I'm definitely NOT a mechanic.
Bit tight and the cables needed care to get out of the way but that's all.

Yes just the tightness of the cables really - next to zero movement in the cables makes re-seating the battery pretty difficult

[HPsauce]

It's been a while, but I think I used bits of string and duct tape to help keep the cables under control. :ROFL:

And IIRC there may be a vent pipe from the battery as well, depending on type.

[Goran]

I was worried I had a current drain somewhere so I bought one of these.
Its not terribly accurate but should be good enough to pick up a serious drain somewhere, and its cheap compared to the highly accurate meters which go into the hundreds of pounds.

http://www.maplin.co.uk/p/uni-trend-ut203-dcac-current-clamp-meter-n41nc

Its DC voltage resolution is 0.01A and accuracy is 2%+5 units (0.05A) up to 40A range.
So if you had a normal parasitic drain in the D2 sleep mode of around 0.1 to 0.2A the reading could be +/- 0.05A out but the error is small enough.
So for example if your parasitic drain turns out to be 0.4A you will know that's too high, even with the +/- 0.06A error its still too high.

My car's reading was 0.18A and it does not kill a 31Ah battery after 10 days. So in my case the reading may be a bit high as at that rate it would drain 43Ah in 10 days.



stats here

http://www.uni-trend.com/en/product/2014_0730_827.html

[Cornershop]

So, do you think a carefully positioned full bottle of water resting on the seat switches could be the cause!? :rolleyes:

Wondered why the seat position was so far off this morning...could barely get in the driving seat.

Wonder also if the motor is now screwed .....

[Lee S]

Naaah. Surely there is an "end of travel" micro-switch that will cut power to the motor when it reaches its end-stop? +++

[Cornershop]

good shout, but kinda hoping there isnt and this is the root cause!

rac man here shortly, will hopefully get a load test on the battery and see whats what.

[HPsauce]

Just tested, motors stop at limit with buttons held down, but presumably there is still some drain from the control circuit. Should be minimal though.

[Cornershop]

thanks for that, time to look elsewhere.

RAC man come and gone - suggest battery is ok, however a possible large drain detected. Unsure if this was because the car hadnt gone into sleep/shutdown mode when the test was started (how long does it take to go into shutdown mode?)

Comments Suspected Diagnosis:
battery flat - charging/starting system tested ok. advise 40min drive to charge and 24hr trickle charge to
fully recover battery.
no load drain above acceptable limit after 5mins, advise further investigation at garage asap.
Battery Test Results
Battery Test
Battery Manufacturer: BOSCH
Rating of battery tested: 720EN
Chemistry of battery tested: FLOODED
Rated Ah of battery tested: 90
Smart charge: No
Battery Test Results
Time: 02/04/2016 14:55
Temperature: 22.2°C
Measured voltage: 2.61Volts
Measured rating: 202EN
State of health: 40%
State of charge: 0%
Test Result: Good Recharge
System Test
Jump pack used:Yes
Starter Avg voltage: 8.03Volts
Starter Avg current: 173.9Amps
Starter result decision: Charge Battery
Alternator voltage (unloaded): 14.02Volts
Alternator voltage (loaded): 13.56Volts
Alternator current (unloaded): 22.7Amps
Alternator current (loaded): 17.2Amps
Charge acceptance test performed: Yes
Diode decision: Normal
Alternator test decision: Normal
First drain test voltage: 2.61Volts
First drain test current: 0.1Amps
Second drain test voltage: 12.06Volts
Second drain test current: -0.9Amps

[Adrian E]

I've got pics of mine in a fairly heavily dismantled condition to access the battery! Boot side trim off and moved to the centre and trim by boot catch removed too

I didn't feel confident keeping everything out the way on reassembly without stripping it that far and it dropped in very easily.

A helping pair of hands or HP's approach would be alternatives but getting it out single handed would be a struggle through that tiny hole

[green A8]

I'd suggest you check the state of the positve feed 'junction box' where the wire splits and feeds the alternator and starter motor. This is located on the O/S chassis leg as is a troublesome earth lead, which can also cause problems. I havn't got any photos of these parts, perhaps others can assist, but I know that just these two connections/wires can wreak havoc when they become corroded.

[Adrian E]

Pics of battery compartment access:

http://forum.a8parts.co.uk/attachment.php?attachmentid=12966&stc=1&d=1459667334

http://forum.a8parts.co.uk/attachment.php?attachmentid=12965&stc=1&d=1459667334

http://forum.a8parts.co.uk/attachment.php?attachmentid=12964&stc=1&d=1459667334

Note that tail light removal is not required! I happened to be in there doing that a couple of weeks before the battery died....

[HPsauce]

All looks very familiar. Pretty sure I swapped over OK without removing the side trim though, but it looks like it would make it a lot easier.

[Cornershop]

I'd suggest you check the state of the positve feed 'junction box' where the wire splits and feeds the alternator and starter motor. This is located on the O/S chassis leg as is a troublesome earth lead, which can also cause problems. I havn't got any photos of these parts, perhaps others can assist, but I know that just these two connections/wires can wreak havoc when they become corroded.thanks, I will. I did get (ask) the garage to do this during the first service in my ownership last year however worth checking again.

Battery undergoing a full recondition charge on the ctek - should be done later this afternoon, however unsure I'll get time to follow Dels procedure that he kindly uploaded.

[ainarssems]

From the report

State of health: 40%

My experience is that battery with 60% of health cannot start the car if left without running for 4 days in summer, 2 days in winter. 25% cannot start car if left for more than 24 hrs in summer.

I am using tester like this http://www.aliexpress.com/item/High-quality-auto-battery-tester/32322722251.html?spm=2114.01010208.3.1.Bjdx9M&ws_ab_test=searchweb201556_6,searchweb201602_5_100 17_10005_10006_10034_10021_507_10022_10032_10020_1 0018_10019,searchweb201603_9&btsid=f9193335-e2ff-46e2-9481-b0ec54ce0376 it only goes to 800A rated batteries but even if you battery have higher rating you can just set it to 800A and get a general idea

I am not sure what the threshold is but I have seen tester telling to replace battery at 61% health an I think I have seen 74% saying good battery so it must be somewhere in-between. I have also found that health stays at 100% for a long time 4-5 years but when it starts to drop below 90% it goes down very quickly couple of months to 25%

[Cornershop]

Fair point - ideally, i'd call RAC back out so they can retest the battery now its fully charged to see what it reads now.

Battery re-inserted after a 28hr reconditioning charge - pretty easily this time, just looped the neg cable around the nearby stud, then managed to push the pos mounting loop away enough to slide the battery past - 30 seconds this time round.

Have hooked up the solar maintainer for now, unlikely i'll get a chance to have a look until the following weekend, which should mean it'll be flat again ....

Tempted to buy a fuse tester (http://www.sealey.co.uk/PLPageBuilder.asp?id=20&method=mViewProduct&productid=13398) - would this allow me to pinpoint the culprit? I guess what i don't know is what is considered an excessive draw and what is normal?

And to perform the test using the above tester, what would be the best procedure? Wait inside the car for X minutes for car to 'sleep' Assuming i disable the interior alarm sensors?

Reading Del's uploaded procedure, I can't interpret the table - ie is it telling me what current draw I should expect or what is considered a high current draw?

Is the old school technique of connecting the multimeter in series and pulling fuses unusable with the Audi?

Sorry lots of questions....

[moltuae]

@Adrian: That seems a bit drastic just to get the battery out.

I've never had to remove any trim to change the battery in any of my D2 8s. Granted it's a bit of a faff and jiggle to get the battery in/out but it's never taken more than a few minutes. I suppose some batteries probably make it more difficult than others, depending on how well they fit. That's actually the first time I've seen behind that piece of trim ... interesting. How easy is it to remove the trim?

[HPsauce]

@Adrian: That seems a bit drastic just to get the battery out.

I've never had to remove any trim to change the battery in any of my D2 8s. Granted it's a bit of a faff and jiggle to get the battery in/out but it's never taken more than a few minutes.I think, to be fair, Adrian had the trim out for other reasons. ;)

And my battery-changing experience is the same as yours. :cool:

[moltuae]

I think, to be fair, Adrian had the trim out for other reasons. ;)

And my battery-changing experience is the same as yours. :cool:

Ah! I thought perhaps there was a quick way to remove it that made it worthwhile.

I have thought about removing that piece of trim once or twice for other reasons, as it happens, but thinking about doing it is as far as got so far. :D

[HPsauce]

I've had the other side trim out many times for various reasons, mostly to do with the alarm. :-(

Never actually had it out fully though, just at a "jaunty angle" as illustrated by Adrian, and I can manage that without removing much at all, just a couple of clips, a velcro'ed plastic panel, and a bit of wiggling.

I think I had the battery side out (similarly) just once as well, to finish off fitting a full cover there (which needed some slots cutting for the mounting lugs) rather than the standard low clip-on divider.

[Adrian E]

It's pretty easy to get it out as HP says. That pic was from when I was changing the tail light, a couple of weeks before the battery died!

I looked at the opening and the size of the battery and just didn't fancy trying to drag it out without an assistant for cable management. Second time going in there took about 5 mins to have the trim out to that level

Eta - I didn't try and remove the battery without trim removal but based on experience with our c5 a6 I expected it to be bloody hard work attempting to get it through a hole just slightly smaller than needed! The a6 was a pig. The s5 is no better as its buried under everything else in the boot including the B&O subwoofer!

[Cornershop]

So, just ran a VCDS scan, which spat out the following. A quick google suggests the alarm horn can be a cause of battery drains ?

Could the 2 issues be related? ie should i inspect/swap the interior sensor initially?

Address 35: Centr. Locks Labels: 8D0-862-257.lbl
Part No: 8L0 862 257 P
Component: CV-Pump, Alarm, RC D17
Coding: 15179
Shop #: WSC 02313
VCID: 428CD0534E4E043138B-4F08

4 Faults Found:
01370 - Alarm triggered by Interior Monitoring
35-00 - -
00958 - Key 4
09-00 - Adaptation Limit Surpassed
01134 - Alarm Horn (H12)
76-10 - Terminal 30 missing - Intermittent
01134 - Alarm Horn (H12)
49-10 - No Communications - Intermittent

-------------------------------------------------------------------------------
Address 45: Inter. Monitor Labels: 4B0-951-178.lbl
Part No: 4D0 951 177 B
Component: Innenraumueberw. D06
Coding: 00001
Shop #: WSC 00000
VCID: 285862FBC832CE6106F-5142

1 Fault Found:
01462 - Anti-theft alarm ultra sonic Sensor (G209)
53-10 - Supply Voltage Too Low - Intermittent

[Delboy]

Some of them fails may be related to a low battery.

Clear them out and see what comes back

[Cornershop]

Thanks Del - I've cleared them but wonder if the alarm horn related codes suggest a leaky alarm battery type issue.

Will give it a few days to see if it returns

[Delboy]

Sounds like a plan +++

[27litres]

Based on an issue I'm having, I was going to suggest the alternator.
My battery goes flat in 3-4 days regardless of how much it's driven (it's my daily). Alternator charges at 13.2 or 13.4 volts. Don't know what amperage it produces, but as it should be charging around 14.4V and long drives don't significantly charge the battery, I'm confident the alternator is stuffed.
There's also anecdotal evidence that a collapsed voltage regulator circuit can actually act as a power drain.

The battery was renewed when the voltage drain was first detected, so I know that's not the issue and the old battery is a good spare now!

I will also check the condition of the chassis stud too, but we don't get salted roads down here!

[Ameiseuk]

Sounds like a regulator failure to me. Get the bearings done while you are that far in

[oldnick]

I have been trying to stop a parasitic drain for some while , as previously reported on another thread here

not being able to effect a cure my current solution [ as the car can stay unused for a couple of weeks after which it won't start ] is to disconnect the earth cable when I put the car in the barn ; after a day the voltage drops to 12.60 and there it stays , so nothing wrong with the battery

the annoying thing is I know where the drain is , just can't find a solution !

if I remove the fuse in the boot which feeds the radio, electric aerial and CD stack the drain drops from 90 milliamp to 25 milliamp , the latter being quite acceptable , the former not

so I disconnected , in turn , each of the above items with the fuse in place , only to find that the drain stays at 90 !

is there anything else on that fuse ?

m'aidez , m'aidez

[27litres]

Sounds like a regulator failure to me. Get the bearings done while you are that far in

I plan to - already bought a genuine voltage regulator and slip ring. Got a good auto elec nearby who'll have bearings in stock. Provided the windings are in good condition she'll be like a new one!
Just waiting for nice weather to affect removal (just coming out of winter here!).


As for other potential failures - the factory mobile phone (where fitted) has been touted as another possible drain device. I've pulled the fuse on mine permanently as 2g is being turned off here in November anyway, so it'll be pretty much useless.
May remove the phone from the arm rest one of these days too!

[HPsauce]

The phone is definitely a drain if you leave the handset installed, otherwise I think probably not.
I accidentally left mine in situ once while away on holiday for 2 weeks, to return to a fully-charged handset and car with a flat battery!

[The_Laird]

The phone is definitely a drain if you leave the handset installed, otherwise I think probably not.
I accidentally left mine in situ once while away on holiday for 2 weeks, to return to a fully-charged handset and car with a flat battery!

I've never had a problem with the phone. The car is left for a couple of weeks every year while we're on holiday, but it starts fine on my return.

[27litres]

I was talking about the factory car phone - no battery...
It is installed on the aux circuit and should time out after x time.
But it can be activated by pressing the power button as I understand it and mine doesn't seem to like not having a sim card in it.
Either way I don't think it caused me any major parasitic drain issues, but as I'll never use it it's pointless giving it any power...