# Battery Drain



## scuzzer (Sep 29, 2014)

Hi guys
I know that there may be a solution already covered on these forums, but here goes
I have had trouble with the left hand battery going flat ,tried everything including VCDS, nothing showing what could cause the problem(although there were loads of faults connected with having a flat battery) 
Cleared all faults and had the battery tested, showed up on tester as faulty, had it replaced .....things O.K for appox three weeks then lo and behold a flat battery again.
Did a VCDS, loads of low/flat battery faults, cleared these yet again....took car for short run and did another VCDS scan this time it showed the following......

Address 18 Aux Heat Labels 3D0-815-005.lbl
Part No 3D0-815-005 AG
Component Standheizung 2426
Shop#: WSC 01065 000 00000
VCID 62C1B451BE54909


2 Faults Found
02251- Heater Unit Locked
0000- -
01412-Glow Plug with Flame Monitoring(Q8)
010- Open or Short to Plus-Intermittent

Question could any of the faults shown be draining the battery ?
Little bit more info..............Voltage meter clipped on battery shows 14.20 volts at start up from flat easing down to 13.86 volts after 10 mins or so. when the battery left to discharge it never goes below 4.80 volts(I assume that whatever is draining the battery will not drain/work below this voltage).

Anybody got any ideas ??
P.S it takes approx 30hrs to discharge the battery 
Cheers Ken


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## phaetonjohn (Oct 24, 2014)

Ken,
I had this problem about a year ago, around 70,000 miles (not kms), with the original battery from Dresden. I load tested the battery, and It was fine. It took about the same amount of time for my battery to go dead also. Very inconvenient when you have a cart full of groceries. I took the car car to a VW dealership (whose owner also owns a Phaeton), and they could not determine anything. Our mechanic could also not find anything wrong, so I had the battery replaced. 1 year later, and still no issue. This may be your easiest choice to take.

Cheers!

-John


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## cbh123 (Aug 25, 2013)

I have an occasional drain issue... and no solution yet. 

I am currently suspicious that my key hook, just inside my garage door, is too close to the car. 
when one of the car antennas detects the presence of a key, it can cause the system to not go to "sleep" 

not sure how likely this is, but I am keeping my keys upstairs for a couple of weeks now to see.


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## arthurgodsake (Nov 26, 2010)

Hi Everyone

Is it possible to tell the age of your LHS battery just by looking at it or do you have to disconnect things?

Thanks

Tim


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## cbh123 (Aug 25, 2013)

if it is a VW battery there should be a sticker with the month and year on it


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## invisiblewave (Sep 22, 2008)

It might also be stamped on top of the negative terminal.


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## n968412L (Apr 23, 2009)

I think it's ONLY stamped on the -ve terminal.


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## n968412L (Apr 23, 2009)

scuzzer said:


> Question could any of the faults shown be draining the battery ?
> Little bit more info..............Voltage meter clipped on battery shows 14.20 volts at start up from flat easing down to 13.86 volts after 10 mins or so. when the battery left to discharge it never goes below 4.80 volts(I assume that whatever is draining the battery will not drain/work below this voltage).
> 
> Anybody got any ideas ??
> ...


Hi Ken - I don't actually know. But I'd be very surprised. These faults tend to stop the heater from working at all - so it's not likely. If you look in the parking heater threads that are active right now, you'll see in there which fuse to pull to make it dead.

30 hours... assuming a healthy battery, that 2 to 3 amps... feels a bit small for the auxiliary heater at it runs both pump and blower too.

13.9V after ten minutes standing sounds fairly healthy to me. 4.8V is about the same as zero volts for a 12V planté battery... it won't do it any good taking it down to 4.8V!

Sorry this is not more helpful... good luck.

Mike


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## invisiblewave (Sep 22, 2008)

n968412L said:


> I think it's ONLY stamped on the -ve terminal.


Not on the US (Mexico) units. There's no stamp, just a sticker.


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## Dangerrous (Sep 14, 2014)

*battery drain*

Okay this is the short version- computer has done two update restarts while I've tried to type a response

Bought car with backstreet dealer booster charge on both batteries
Accessories battery wasn't performing too well
Checked specs and bought a new battery
Took out old Bosch battery only to find it date stamped 2012 and guaranteed for 4 years
Found that standard battery charger doesn't work too well for AGM batteries
Bosch battery was probably okay, just needed charging correctly
Ctek battery charger purchased to keep my new battery fully charged, first charge after two weeks of car in garage SIXTEEN HOURS!

Is it possible that your battery just needs Desulphation-Soft start-Bulk-Absorption-Analyse-Float-Pulse (ctek battery charge stages) to rejuvenate it?
Love my CTEK
Darren


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## invisiblewave (Sep 22, 2008)

I believe the AGM batteries are particularly susceptible to death after a deep discharge. I spent quite some time trying to resurrect mine with that desulphation program, but my conclusion was that it's likely more of a marketing tool than a useful feature. I ended up buying a new battery. You should also take a close look at the RH battery. If that's weak, it will suck juice from the LH battery during starting, which can cause all kinds of electronic problems. If the system is resetting during starting, the RH battery might be the source of the problem. It's also a lot cheaper.


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## n968412L (Apr 23, 2009)

invisiblewave said:


> Not on the US (Mexico) units. There's no stamp, just a sticker.


even on the factory fitted ones?


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## invisiblewave (Sep 22, 2008)

My original batteries weren't stamped. They come with a little round sticker. The RH battery looked so cheap and nasty when I picked it up the other week, that I questioned the parts person about whether it was really a genuine VW battery, it says "Made in Mexico" on it. I wonder if they shipped 'em over without batteries?


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## WillemBal (Nov 20, 2010)

scuzzer said:


> Hi guys
> 2 Faults Found
> 02251- Heater Unit Locked
> 0000- -
> ...


Hi Ken,

This indicates an unusual problem with your heater unit. I would suggest to pull the fuse of the heater unit in order to eliminate the heater as possible cause for the drainage of the battery.

Did you also see (besides the heater faults) any of the below mentioned faults?

Address 07: Control Head 
00668 - Supply Voltage Terminal 30 
002 - Lower Limit Exceeded - Intermittent
-------------------------------------------------------------------------------
Address 09: Cent. Elect. 
00907 - Intervention load Management 
000 - - 

In the case you haven't seen any of these faults then it is even more probably that the heater causes the problem since the drainage then apparently occurs without the above two controllers monitoring the battery supply voltage.




> Little bit more info..............Voltage meter clipped on battery shows 14.20 volts at start up from flat easing down to 13.86 volts after 10 mins or so.


That is perfect! It is indicating that the generator charges your battery properly.



> when the battery left to discharge it never goes below 4.80 volts


It normally never should drop below 9 Volts and drainage down to 4.8 Volts possibly ruins one or more of the cells in the battery. I think that only defective electronics (like the heater or its controller) can cause this deep discharge. 

Another question: do you lock the car or do you leave it unlocked (for example in your garage). The P normally keeps on consuming so electricity for various controllers while it can take up to 30 minutes before the last consumer shuts down. Locking the car speeds avoids possible unnecessary prolonged operation of controller.

Regards,
Willem


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## scuzzer (Sep 29, 2014)

Hi guys
Thanks for your thoughts on the problem so far, although I did mention it briefly in my original post, it seems to have got missed, namely I have fitted a new left hand battery(the old one was 7 years old ). It was the old battery going flat that prompted the fitting of a new one and I had hoped a solution to the problem.
However I have now purchased a dedicated AGM battery charger and what a revelation it turned out to be, my volt meter showed 12.46v, but when I connected the charger its screen said that the battery had indeed got 12.44v but it was in fact only 20% charged, so I intend to charge to 100% and then leave the car for the usual 30+ hours and see what happens?.................I have by the way pulled the aux heater fuse left for 15secs then put back in as described on this forum
Thanks again
Ken


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## invisiblewave (Sep 22, 2008)

How old is the RH battery? The LH battery is unlikely to get above about 12.7v in my experience, and probably not even that high, even when new and fully charged.


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## scuzzer (Sep 29, 2014)

Hi invisilbewave
The right hand battery appears to be of 2006 vintage,however there has never been an issue starting the car even when left hand battery is flat/low.
Just finished getting the left hand battery up to 100%, put the smart charger onto the right hand battery, said it was fully charged !
Now I know that both batteries are up to speed,going to wait and see if there is any drain.
Will let you know what happens
Regards
Ken


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## invisiblewave (Sep 22, 2008)

Don't discount RH battery problems. When the RH battery is bad, it sucks juice from the LH battery automatically every time you start the car. Listen for a clunk from the trunk a few seconds after starting, that's the battery relay. If the RH battery is bad, it has the potential to damage your new LH battery over time, especially if you do a lot of short trips. For the price and ease of fitment, it's probably a good investment to change the RH battery, it's cheap and it's a 5 minute job.


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## WillemBal (Nov 20, 2010)

scuzzer said:


> ...However I have now purchased a dedicated AGM battery charger and what a revelation it turned out to be, my volt meter showed 12.46v, but when I connected the charger its screen said that the battery had indeed got 12.44v but it was in fact only 20% charged, so I intend to charge to 100% and then leave the car for the usual 30+ hours and see what happens?
> Thanks again
> Ken


Hi Ken,
There may be a possibility that your new battery wasn't fully charged when it was installed. A normal Phaeton consumes about 30 mA after locking and all consumers switched off, however a poor initial state may have cause some complexing factors, such as electronics trying to function properly with insufficient power. In other words, electronics may fail to switch on properly, causing problems when the same or other controller electronics try to switch them off. 

I noticed that you reported some voltages prior and during charging of the battery. The voltages you observe greatly depend on many factors, i.e. whether the battery is connected to the car or not, whether consumers are on etc. The Ctek battery charger has a very limited charging capacity as far as I know, perhaps 3 Amps or 5 Amps max. So with the trunk lid opened, the car may already consume more than the charging capacity, so whatever you measure then can mean anything.
The numbers which are produced by the Ctek and your voltmeter can only be reliably interpreted when the battery is not connected to any load. So if your voltmeter showed 12.44 Volts while the battery was connected to the electrical system of the P, then the battery was pretty close to full. With a Ctek charger it is absolutely necessary to close the trunk lid and lock the car in order to make sure that the charging process is not affected by consumers in the P., or otherwise disconnect the battery from the electrical system prior to charging.



invisiblewave said:


> The LH battery is unlikely to get above about 12.7v in my experience, and probably not even that high, even when new and fully charged.


That is right in case the battery is connected to the electrical system. A battery which is (slightly) loaded indeed never shows a voltage above 12.7 Volts. Only during charging the voltage increases above this value. A fully charged battery may show a voltage of 14.2 when fully charged. It may show slightly less when the charger is disconnected after charging while not being loaded by any consumer. It may still show a voltage of 14 Volts one week after disconnecting the charger. However when a small load is applied (like a car bulb) for a minute or so, then the voltage quickly drops to 12.7 Volts.




scuzzer said:


> .................I have by the way pulled the aux heater fuse left for 15secs then put back in as described on this forum


I meant to say that pulling the fuse and leaving it out for a week or so would helpfull to diagnose whether or not the heater is a possible cause of drainage of the battery. Or do you frequently use the standheater these days?

Willem


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## Dangerrous (Sep 14, 2014)

*ctek*

Just for info, I've got one of the new larger 8amp chargers due to size of the agm battery. I can charge my battery with the boot open in the garage, charging time isn't an issue as this car is only used weekends
Darren


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## scuzzer (Sep 29, 2014)

Hi Guys
Just a quick update on this battery situation.
Had the right hand battery tested (twice) today, checks out as O.K, also had left hand one tested as well, thankfully also O.K. Both were disconnected at time of testing.
My thought at the moment are going along the lines of WillemBal that maybe, just maybe the left battery was not fully charged at the time of fitting and could not keep up with demand.
Also at this late stage I know this will sound totally daft but I am still not sure I have a auxiliary heater? I know the Vag Com is showing faults that says I do, but ...silly question do all Phaetons have aux heaters?
I have a fuse(16) marked as supplementary heating system could this be the same(it the one Ive been pulling).......last silly question, if this is the fuse can I pull it and safely run the car with it removed?
Confused ????
Thanks 
Ken


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## invisiblewave (Sep 22, 2008)

How did you test the battery? I had numerous tests done on mine, some said it was good, some said it was bad. Even the same test tool used twice within a few minutes showed different results. I knew my LH battery wasn't in tip-top condition just from my own simple voltage testing, and I suspected the RH battery because I could regularly hear the relay kicking in when starting.

All the batteries I've bought from VW have either been old at the time of purchase, or far from fully charged. With the latest two, the second thing I did was put them on charge (the first thing was to check the date when I bought them), both batteries took a long time to reach fully charged status on the CTEK.


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## WillemBal (Nov 20, 2010)

scuzzer said:


> ... silly question do all Phaetons have aux heaters?
> I have a fuse(16) marked as supplementary heating system could this be the same(it the one Ive been pulling).......last silly question, if this is the fuse can I pull it and safely run the car with it removed?


Hi Ken,
Some Phaetons do have aux heaters as it is an option at least in Europe. Fuse SC 16 is indeed the (25 Amp) fuse which is needed for the aux heater. You can safely pull this one for experimental purposes as it only powers the heater. You may also leave leave the fuse where it is in order to try to switch it on.

You can control the heater with a special remote control which looks a little different than the normal keyfob. You can also control the heater by means of the A/C menu. 
Simply press the bottom button on the row at the right hand side of the screen.
The text in the screen probably says something like "other" or "next". The next screens shows you the rear climate controls. At the same position (right hand bottom) you will probably see a text like "Stand Heater" or "Interior heater". I'm not sure because my menu's are in Dutch.
On the next menu you will see some timing controls in the centre. You will als see the text "Heater" in the top left side of the screen. Pressing that button starts the heater.

It may not switch on when not all conditions are met. You will need a fair battery, sufficient fuel and the controller needs to be in good condition. If it does not switch on with a cold engine and battery & fuel ar OK, then there may be a fault in the controller.

You may use the VCDS to get access to the controller. Simply select controller 18, then see if any faults exist, then clear them and try again to switch it on.
When faults keep returning (after each attempt to switch it on) then please report the faults so we may help you further.

Willem


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## phaetonjohn (Oct 24, 2014)

On my screen, it says "Other Functions", and "Residual Heater". This just turns on the fan and pumps out heat, not an actual separate heater.


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## WillemBal (Nov 20, 2010)

I guess that the menu may be different on Phaeton's without installed heater. When the heater is installed and the engine is hot the function is the same as on Phaetons without heater. 
Btw I forgot to mention that the operation of the heater is indicated on the instrument panel by means of some parallel ribbled vertical lines (green). Perhaps this indicator is also illuminated when the residual heat function is switched on.

Willem


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## phaetonjohn (Oct 24, 2014)

The icon shows up on the screen between the gauges? And where? I have not noticed such an icon, but I may not have been looking very closely.

-John


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## WillemBal (Nov 20, 2010)

The icon shows up somewhere in the middle of the screen. I'll take a photo tomorrow. 
Some interesting reading stuff and photos of the heater, the menu's and troubleshooting can be found here:

*Parking-Heaters-(Standheizungen)-Retrofitting-Troubleshooting*


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## ravenflies (Oct 31, 2013)

Hello John,
I did take some pictures showing how it looks with a working heater installed.

*Under "Other functions":*









*Under "Auxiliary heater", heater off:*









*Under "Auxiliary heater", heater on:*









*Icon indicating heater on:*









/Lennart


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## phaetonjohn (Oct 24, 2014)

Lennart,

I will try to take some pictures tonight. Where yours says "Auxiliary Heater", mine just says "Residual Heat". I also don't have the "Solar Ventilation". So... this heater is gas powered?

-John


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## invisiblewave (Sep 22, 2008)

I don't believe the NA cars had auxiliary heaters did they, just the residual heat function?


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## ravenflies (Oct 31, 2013)

phaetonjohn said:


> Where yours says "Auxiliary Heater", mine just says "Residual Heat". I also don't have the "Solar Ventilation". So... this heater is gas powered?


OK, Residual Heat just use the built up heat from the Engine cooling system and distribute that as long as there is any heat and as long as it does not risk draining the battery.
Solar ventilation just powers the blower for cabin air to keep the cabin ventilated, uses no power from battery, only from the solar panel in the sun roof.
Auxiliary Heater uses petrol or diesel for the heating and battery power to run it. It looks like your car does not have the Auxiliary Heater. 

/Lennart


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## scuzzer (Sep 29, 2014)

*Battery drain*

Hi Guys
Thanks for all your input so far, bit more info for you to chew on.
Tried to access the residual heat function, the screen says function unavailable, just like the phone !
Maybe I dont have this function after all??
Cheers 
Ken


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## invisiblewave (Sep 22, 2008)

You probably do, but as I posted elsewhere recently, the residual heat function is somewhat mercurial, there are numerous preconditions which need to be satisfied before it'll work. If you have any kind of LH battery issue, you'll likely never see the button lit. Assuming your battery is ok, to get it to work you need to 1. Make sure the ambient temperature is cold enough (I don't remember the exact temp, but it needs to be roughly cold enough to freeze the balls off a brass monkey). 2. Drive the car until the engine is hot (I thought the threshold was 160F, but recently mine hasn't been functioning until hotter than that). 3. Stop the car, turn the engine off BUT DON'T REMOVE THE KEY AND DON'T OPEN THE DOOR. 4. The button should now be lit, press it.

If your LH battery is low, if the engine isn't hot enough, if the ambient is too warm, or if you open a door prior to activation, residual heat will not be available. In practice, it's almost impossible to use, even when all the conditions are met the chance of you remembering not to instantly go through your normal routine when you stop is slim. In my case, switching off the engine and removing the key tends to happen in one subconscious motion, quickly followed by opening the door. Once the door is opened, you have to restart the engine to activate residual heat (I think it's the same once you've removed the key, but I don't recall). On top of all that, it doesn't help much unless you're away from the car for a fairly specific amount of time. If you're only gone a few minutes, the car will likely still be warm anyway, and if you're gone for an hour the residual heat will long since have disappeared. I'd rate it as marginally more useful than TPMS.


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## scuzzer (Sep 29, 2014)

*residual heater*

Hi Invisiblewave
I have tried accessing the residual heater as per the owners handbook without success, it does not vary to much from your version, so when conditions allow(ie freezing cold) I will try your instruction and report back
Cheers
Ken
P.S Is there also secret to access the phone ?????


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## ravenflies (Oct 31, 2013)

Hi Ken,
I can agree to a point with Invisiblewave, but I think it is a little more useful than that. With a LH battery some years old it works fine in my car for the fifteen minutes stops. I use it quite often for this. It works after a 15 km ride from cold in outside temperatures below + 5 degrees Celsius. I do have the auxiliary heater in my car, but when the coolant temperature is up in normal working temperature the start button is greyed out and can't be used in that case. Then it is quite nice to keep the temperature up for about 15 minutes or so.
Regarding access to the phone: I have that problem from time to time, the secret there is the number of starts between loss of access. It varies between about 50 and about 250, more often at the higher end of the scale. After the next start it works again. 

/Lennart


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## phaetonjohn (Oct 24, 2014)

Here is what my screen looks like...

*Initial Climate Screen*


*"Other Functions" Screen*


*Residual Heat Function ON*


*Main Climate Screen with Residual Heat ON*


I noticed no icon on the dash. Is the Auxiliary heater on a timer/scheduled start? AND... can it be started by remote?

-John


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## cbh123 (Aug 25, 2013)

North American cars did not have auxiliary Heat... Only residual heat.

Some ROW gas cars have the aux heater 
Most ROW diesel cars have it..

Unless you are REALLY into researching parts, ordering them from all over the world.. And then getting exceptional with modules and vagcom coding... I suggest you just read up and lean how to use the residual heat function. 
It has been discussed to death here. (Not t mention you could read the owner's manual)


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## ravenflies (Oct 31, 2013)

phaetonjohn said:


> I noticed no icon on the dash. Is the Auxiliary heater on a timer/scheduled start? AND... can it be started by remote?


Hi John,

The Auxiliary heater is on a timer/scheduled start AND can be started manually via the menu AND It can be started by remote (separate).
The recidual heat does not show any icon, it indicates only active Auxiliary heater. I am convinced your car does not have any Auxiliary heater, the menu lacks the last level where the Auxiliary heater should be found.

/Lennart


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## phaetonjohn (Oct 24, 2014)

Lennart and cbh123,

Okay, this makes more sense now... I've discovered that even if the key is out, you can hold the "ON/DARK" button for a few seconds, and then access the residual heat. 
I kind of wish that I had this Aux. Heater, but I don't drive the car every day (only 2-3 times a week). Thank you all for your comments! 
I've read the owners manual once, but as PanEuropean once said...


> PanEuropean "reading the owner's manual that came with my new car (Tolstoy's 'War and Peace' was a quicker read)"


(http://forums.vwvortex.com/showthre...ge-carpet-(and-interiors)&highlight=War+Peace)
I do not remember it saying anything about an Aux. Heater, but it's easy to overlook something.

Thank you!


-John


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## scuzzer (Sep 29, 2014)

Hi Guys
Some good news (I think)
(1) I have left the car for two periods exceeding 75hrs each and so far I have had no left battery problems (30 hrs was the previous best). Fingers crossed 
(2) Following Invisiblewaves instructions on how to access it, I am pleased to announce that I do have a residual heater and having played about with it, I can confirm it is now switched off !!
Many thanks again too all for your help on this problem
Cheers 
Ken


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## invisiblewave (Sep 22, 2008)

It's probably working because of the brass monkey weather you're currently enjoying back in Blighty!


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## phaetonjohn (Oct 24, 2014)

Ken,
Congratulations!

-John


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## n968412L (Apr 23, 2009)

scuzzer said:


> Hi Guys
> Some good news (I think)
> (1) I have left the car for two periods exceeding 75hrs each and so far I have had no left battery problems (30 hrs was the previous best). Fingers crossed
> (2) Following Invisiblewaves instructions on how to access it, I am pleased to announce that I do have a residual heater and having played about with it, I can confirm it is now switched off !!
> ...


Hi Ken - hope the good news persists! Re (2) - I don't think you can really leave it switched on... if you do, it turns itself off either when the heater matrix goes cold (or it's on a timer... not sure) or when the battery volts start to sink. So I don't believe it should be a source of drain... and certainly not an issue for a healthy battery.

Regards

Mike


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## phaetonjohn (Oct 24, 2014)

It does shut off by itself (either by a low battery, or by no heat left).


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## bjoroy (Mar 2, 2016)

Hi! Very old thread, but as a FYI: I just experienced battery drains on my 2006 3.0TDI. No power after leaving the car over night. Replacing the aux. battery did not help, so after an internet session I stumbled upon this thread. My parking heater was apparently not accessible via VCDS anymore, so I gave it a shot and ordered a refurbished one on eBay for about $300. Voila! The battery drain is gone and the parking heater works again! Attached a picture of the PCB from my old heater... no wonder it was messing everything up.


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