Username or Email Address
Do you already have an account?
Forgot your password?
  • Log in or Sign up

    VWVortex


    Results 1 to 35 of 73

    Thread: V10 LH Battery Replacement

    Hybrid View

    1. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      02-06-2012 03:48 PM #1
      Twice now I have needed to open the car with the key.

      It starts so it seems like the RH battery is OK and as I leave the car running the LH battery starts to retain some charge and all my functions come back however the next morning it's all gone.

      Seems like the old chestnut of the first cold spell exposing an ailing battery so my question is have you all been replacing your batteries with the OEM item and what price have you been paying?

      With thanks in anticipation,
      Sreven

    2. Member WillemBal's Avatar
      Join Date
      Nov 20th, 2010
      Location
      Putten, Netherlands
      Posts
      736
      Vehicles
      Phaeton 04W12, Crystal Grey & Extended Leather, '03AudiA4 1.8T, '51 BMW R25
      02-06-2012 06:17 PM #2
      Quote Originally Posted by Expoman View Post
      It starts so it seems like the RH battery is OK and as I leave the car running the LH battery starts to retain some charge and all my functions come back however the next morning it's all gone.
      Hi Steven,
      Just a small test to see whether your battery retains charge is to switch on the ignition after you have switched off the engine (after a long trip). With ignition on and engine off, just watch the dash voltmeter reading for a while. Then switch on the high beams. The voltmeter should read above 12 Volt and the dip in voltage after switching on the high beams shouldn't be more than 0.25 Volts.
      If you have one, you might want to try to recharge the battery and see if this improves the situation.

      I use my stand heater twice a day now and as a result, I put the battery on the charger at least once a week. Without it, I'm pretty sure that the heater cannot be switched on most of the time. I don't want to risk that!

      Willem

    3. Junior Member Appaz's Avatar
      Join Date
      Oct 30th, 2009
      Location
      Latvia, Europe
      Posts
      98
      Vehicles
      2004 V10 4seat
      02-07-2012 09:46 AM #3
      I had similar problems some while ago.
      At first i changed both batteries. Did not help.
      After that problem was found that one fuel pump did not shut off on engine stop, and during night this fuel pump did eat out battery.

      I might mistake by details, as I am not mechanic, but it was something like that
      Ed Smirnoff.

    4. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      02-07-2012 03:03 PM #4
      Many thanks Gentlemen.

      That's a very useful test Willem, I'll give it a try at the weekend.

      I've got a charger so once the snw has gone I'll give the battery a good long charge, part of the problem is that the car is not being used me at the moment.

      All best,Steven

    5. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      02-10-2012 01:25 PM #5
      I went to run the Phaeton today - in the last 2 weeks it's been driven once, about 5 miles and parked outside in continuous minus temperatures.

      I had to let myself in with the key and start by twisting left then right but then it started and ran perfectly.

      I sat whilst it got up to about 60 C engine temperature (20 mins at tick over) and the voltmeter was showing about 14.25 dropping to 14 when lights switched on and full =beam engaged.

      All worked fine except the aircon was slow to heat up the car and the screen was active but dimmed so clearly the LHS battery is suffering - I opened the battery compartment and the battery had frost on it!

      These old eyes couldn't read the date stamp on the terminal so I shall return in the morning with magnifying glass (isn't ageing tedious?) to determine how old said battery is?

      Willem, haven't been able to perform your test because car has not been on a long run but it will be in a weeks time because we are off to England for one of our shows - Coventry of all places.

      My question is - does this sound like a battery that is looking to be retired or, given the continuous load placed on it, lack of use and long period of low temperatures, is likely to recover after being drive a couple of thousand kilometres?

      Your help and advice will be, as always, much appreciated.

      All best,
      Steven

    6. Member EnglishPhaeton's Avatar
      Join Date
      Dec 6th, 2010
      Location
      Harrogate, UK
      Posts
      866
      Vehicles
      Black 2006 Phaeton V10 TDi, Black 2005 V10 TDi LWB, Laser Blue Golf 2.0 GT TDi
      02-10-2012 01:42 PM #6
      Quote Originally Posted by Expoman View Post
      I went to run the Phaeton today - in the last 2 weeks it's been driven once, about 5 miles and parked outside in continuous minus temperatures.

      I had to let myself in with the key and start by twisting left then right but then it started and ran perfectly.

      I sat whilst it got up to about 60 C engine temperature (20 mins at tick over) and the voltmeter was showing about 14.25 dropping to 14 when lights switched on and full =beam engaged.

      All worked fine except the aircon was slow to heat up the car and the screen was active but dimmed so clearly the LHS battery is suffering - I opened the battery compartment and the battery had frost on it!

      These old eyes couldn't read the date stamp on the terminal so I shall return in the morning with magnifying glass (isn't ageing tedious?) to determine how old said battery is?

      Willem, haven't been able to perform your test because car has not been on a long run but it will be in a weeks time because we are off to England for one of our shows - Coventry of all places.

      My question is - does this sound like a battery that is looking to be retired or, given the continuous load placed on it, lack of use and long period of low temperatures, is likely to recover after being drive a couple of thousand kilometres?

      Your help and advice will be, as always, much appreciated.

      All best,
      Steven

      Hey Steven,

      you could always take a "rubbing" of the date stamp

      Stu

    7. Member n968412L's Avatar
      Join Date
      Apr 23rd, 2009
      Location
      Ramsbottom, UK
      Posts
      1,748
      Vehicles
      2008 3.0TDI Phaeton; 2009 1.4 Tiguan; 2005 V10 Phaeton; 1992 Golf Mk 2 Driver 1.8
      02-10-2012 01:44 PM #7
      I have similar dilemma.

      Battery age on the LH terminal seems pretty easy to read - it's stamped clearly right on the top on the OEM battery. Mine says 06 05 - which I think makes it close to 7 years old.

      It's clearly not well. It won't put the lights on in the boot... and after 30 mins with the key in the ignition but engine not running it wont turn the headlights on.

      I charged it overnight with CTEK charger mid week.. for about 12 hours... didn't get to the maintenance charge in that time.. but subjectively it was better afterwards. Will try to do more charge over weekend... but I suspect I'm probably wasting my time. Looking for a keenly priced replacement.

      On V6 with 4 year old battery that appears very healthy...I've noticed if I run the parking heater early in the AM after overnight frost for 30 minutes, by the time I come to start the car, the voltmeter in the dash is showing 11.5 volts -but all the other electrics seem to work fine.. ie the car hasn't started shutting them down. As soon as engine starts volts jump right back to 14V. I assume this is normal, otherwise the parking heater itslelf would have shut down.

      I feel the need to find a recording digital voltmeter..... I'm sure Willem will have one of these...

      Regards

      M

    8. Member
      Join Date
      Aug 5th, 2008
      Location
      Maitland, FL USA
      Posts
      928
      Vehicles
      2004 V8 Phaeton, 2005 V8 Touareg
      02-11-2012 01:11 PM #8
      Quote Originally Posted by Expoman;

      Seems like the old chestnut of the first cold spell exposing an ailing battery so my question is have you all been replacing your batteries with the OEM item and what price have you been paying?

      Sreven
      Steven:

      I don't know how cold it has been, but battery capacity drops significantly with temperature. So if the battery is very cold, capacity could be a small fraction of full capacity. So demands on the battery probably increase with decreasing temperature, while capacity is dropping. I know temperature has been mentioned in numerous posts but wasn't sure if it's significance had been truly noted.

      Jim X

    9. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      02-11-2012 01:42 PM #9
      Quote Originally Posted by Jxander View Post
      Steven:

      I don't know how cold it has been, but battery capacity drops significantly with temperature. So if the battery is very cold, capacity could be a small fraction of full capacity. So demands on the battery probably increase with decreasing temperature, while capacity is dropping. I know temperature has been mentioned in numerous posts but wasn't sure if it's significance had been truly noted.

      Jim X
      Thanks Jim, yes it has been extremely cold, below zero day and night for about 10 days coinciding with the car having been used very little.

      Best
      Steven

    10. Member WillemBal's Avatar
      Join Date
      Nov 20th, 2010
      Location
      Putten, Netherlands
      Posts
      736
      Vehicles
      Phaeton 04W12, Crystal Grey & Extended Leather, '03AudiA4 1.8T, '51 BMW R25
      03-14-2012 06:28 PM #10
      Quote Originally Posted by Expoman View Post
      Willem, I think I am grasping at straws, perhaps I should invoked the help of the almighty with a pause for prayer!
      and...

      Their guess is that in the UK at Listers of Coventry they tested the RHS battery which is fine.................
      Next time you think of bringing your car to Blacklisters, you'd better say your prayer ...
      But seriously, isn't the dealership we put our trust in, the most complexing factor in owning a Phaeton?

      Willem

    11. Moderator Paximus's Avatar
      Join Date
      Aug 26th, 2011
      Location
      Dorset, UK
      Posts
      2,704
      Vehicles
      2005 Phaeton V10 swb 4-seat, Jeep Commander Hemi, Ssangyong Korando
      03-14-2012 08:39 PM #11
      I asked for some floorpan bungs in advance of a booked service, but unfortunately the wrong ones were ordered and had to be re-ordered. So they weren't fitted, but arrived the day after. They were supposed to be posted to me, but never arrived. So I just drove 140 miles to the dealer (not solely for that!) and paid £4 for a second lot.

      We will see what happens.

      But their coffee is OK and the workshop is very nice.

      At least the new floor display car was a lovely black/sonnenbeige SWB TDI with sunroof, so I had to sit in it to feel the difference. But it just felt exactly like mine, so not much incentive...

      Chris

    12. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      03-15-2012 03:50 AM #12
      Quote Originally Posted by WillemBal View Post
      and...



      Next time you think of bringing your car to Blacklisters, you'd better say your prayer ...
      But seriously, isn't the dealership we put our trust in, the most complexing factor in owning a Phaeton?

      Willem
      Hi Willem,

      I entirely agree.

      From what I have seen in the UK (2 dealers), the VW standard is simply not that which can support a car of the complexity and value of the Phaeton. Alan Day in London was simply appalling, Listers in Coventry appeared better at face value (although I did not visit their premises) but clearly were well short of the mark in terms of care and attention to doing the work itself although they did collect and deliver the car back on the same day and I formed the impression that they were honest and the Service manager was pleasant, courteous and professional as was the guy who collected and delivered the car.

      I only have experience of 1 dealer in France but it's another world - the Phaeton Tech obviously knows the car intimately and clearly enjoys what he does and the service manager is excellent. It's the little touches - when you arrive at the appointed time,(these are split by the half hour so there is no hanging around while they deal with the previous person) there is a stand in the service reception saying "Welcome Mr.(Your name)".

      Sure, doesn't do a thing to the car but it speaks of an attention to detail which suggests that will be carried through in all things that they do and that, in my experience with them, is the case.

      They removed my CD player and fitted the Solisto for me free of charge when I popped it in without an appointment a couple of months ago and that for me is real customer service.

      Best,
      Steven

    13. Member WillemBal's Avatar
      Join Date
      Nov 20th, 2010
      Location
      Putten, Netherlands
      Posts
      736
      Vehicles
      Phaeton 04W12, Crystal Grey & Extended Leather, '03AudiA4 1.8T, '51 BMW R25
      02-12-2012 07:11 PM #13
      Quote Originally Posted by n968412L View Post
      Willem - I think this should read "the charge current is never more than 22A and the..."??
      If so, I agree.
      Oops, a slipper of the keyboard. Thanks for paying attention and letting me know!


      I have battery that still seems to be very low charge... and it had a run of 230 miles last week - about 4 hours - in the daylight with not too many accessories running. So that should be good for 70+ Ah, yet the battery still seems to be weary... I guess there's not much option other than to change it!
      I agree; 4 hours of driving is more than enough. Btw... you can switch on as many consumers as you want while driving. It doesn't affect the charge current in any way. When you switch on a major consumer, such as the high beams or one of the electrically heated components, you will notice a slight glitch in the dash voltmeter, which will recover soon after.

      BTW, how do you know the upper charging limit of 22A?
      Excellent question. To make a long story short: I first assumed it, then I verified it using a (calibrated) Fluke Ampere clamp.
      I assumed it because most lead acid batteries are "bulk charged" in 4 hours. Meaning that about 90% of the charge cycle is done with 95Ah x 90% / 4 hour = 21 Amps. I measured 22 Amps, so that was close enough for me.

      Willem

    14. Member n968412L's Avatar
      Join Date
      Apr 23rd, 2009
      Location
      Ramsbottom, UK
      Posts
      1,748
      Vehicles
      2008 3.0TDI Phaeton; 2009 1.4 Tiguan; 2005 V10 Phaeton; 1992 Golf Mk 2 Driver 1.8
      02-13-2012 02:41 AM #14
      Quote Originally Posted by WillemBal View Post
      I agree; 4 hours of driving is more than enough. Btw... you can switch on as many consumers as you want while driving. It doesn't affect the charge current in any way.
      Of course you're right... but I'm so old that I started driving in the '70s and the vehicles I could afford then all had dynamos... where the amount of high current consumers did affect the battery charge. I had a diesel landrover with two BIG 6V batteries - one in the engine bay and one under the passenger seat. They only got fully charged once - and that was on a three day trip to Scotland... I think I'd be driving for 20+ hours before they were full. I could tell they were full because the ammeter was on zero, but when I pressed the brake pedal, the 4A to operate the brake lights came from the battery as its internal resistance wold be lower than the dynamo... because until then pressing the brake just reduced the charge going into the battery.

      Quote Originally Posted by WillemBal View Post
      Excellent question. To make a long story short: I first assumed it, then I verified it using a (calibrated) Fluke Ampere clamp.
      I assumed it because most lead acid batteries are "bulk charged" in 4 hours. Meaning that about 90% of the charge cycle is done with 95Ah x 90% / 4 hour = 21 Amps. I measured 22 Amps, so that was close enough for me.
      That's good to know - thanks.
      Regards
      Mike

    15. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      02-13-2012 10:34 AM #15
      Quote Originally Posted by n968412L View Post
      Of course you're right... but I'm so old that I started driving in the '70s and the vehicles I could afford then all had dynamos... where the amount of high current consumers did affect the battery charge. I had a diesel landrover with two BIG 6V batteries - one in the engine bay and one under the passenger seat. They only got fully charged once - and that was on a three day trip to Scotland... I think I'd be driving for 20+ hours before they were full. I could tell they were full because the ammeter was on zero, but when I pressed the brake pedal, the 4A to operate the brake lights came from the battery as its internal resistance wold be lower than the dynamo... because until then pressing the brake just reduced the charge going into the battery.



      That's good to know - thanks.
      Regards
      Mike
      And Mike,

      What a pain it was having that guy with the red flag walking in front of you all the way.................

      Best,
      Steve

    16. Member WillemBal's Avatar
      Join Date
      Nov 20th, 2010
      Location
      Putten, Netherlands
      Posts
      736
      Vehicles
      Phaeton 04W12, Crystal Grey & Extended Leather, '03AudiA4 1.8T, '51 BMW R25
      02-12-2012 07:39 PM #16
      Quote Originally Posted by laser21 View Post
      Should I try charging it again? Is this normal behaviour when the battery is dead?
      Hi Lukas,
      Mike and Jim already gave very good comments. A little trick that I sometimes do to check the battery status, is to switch on the ignition without starting the engine. The dash voltmeter then will indicate the charge status (or better: the voltage of the battery with about 20 A load). After a charge cycle with your charger during the night, the next morning the dash meter should read at least 12.5 Volts (possibly a little less due to the low outside temperature)

      Quote Originally Posted by n968412L View Post
      I don't really trust the voltmeter on the dash.
      During our next GTG, I will check it for you. This "needle instrument" is surprisingly accurate.

      Willem
      Last edited by WillemBal; 02-12-2012 at 07:48 PM.

    17. Member n968412L's Avatar
      Join Date
      Apr 23rd, 2009
      Location
      Ramsbottom, UK
      Posts
      1,748
      Vehicles
      2008 3.0TDI Phaeton; 2009 1.4 Tiguan; 2005 V10 Phaeton; 1992 Golf Mk 2 Driver 1.8
      02-13-2012 02:49 AM #17
      Quote Originally Posted by WillemBal View Post
      During our next GTG, I will check it for you. This "needle instrument" is surprisingly accurate.
      I'm very suspcious. I think it might be damped like the coolant temperature guage is.... although how do you tell as it's not really analogue, is it?

      Where would you pick up and log system volts with VAG-Com??

      I've certainly been measuring 11.5V at the battery with a branded digital multimeter,whilst the dash voltmeter is showing 12.5V. Not followed up on this... but it's on my list of things to check. I have not yet ruled out the multimeter.. but as it's showing readings I believe for the conditions.. and it seems to follow the battery volts up to 14.5V when appropriate, I think it's OK. I've certainly measured a different voltage (with ignition on) at the cigar ligher socket next to the gear selector to that which is displayed in the dash.... but again same multimeter.

      I'll keep researching it!

      regards
      M

    18. Junior Member
      Join Date
      Jan 25th, 2012
      Location
      Slovakia
      Posts
      79
      Vehicles
      2006/VW/Phaeton W12
      02-13-2012 03:09 PM #18
      Ok, so after charging the battery, it seems that the Phaeton is satisfied The currents are about 13.8V on the battery, aswell as on the analogue dash readout.
      The problem with the trunk remains though It doesnt respond to either command - press on VW emblem, remote open, or the one in the drivers door. Only the turn signals flash. When I open it with the key, and want to close it - no response to the close button.
      I found a thread, where people say, that the trunk can behave strangely when something is not right. I tried all possible combinations, still no luck.

      Any suggestions? Expoman does your trunk work now?

      Thanks

    19. Member WillemBal's Avatar
      Join Date
      Nov 20th, 2010
      Location
      Putten, Netherlands
      Posts
      736
      Vehicles
      Phaeton 04W12, Crystal Grey & Extended Leather, '03AudiA4 1.8T, '51 BMW R25
      02-13-2012 03:24 PM #19
      Quote Originally Posted by laser21 View Post
      Ok, so after charging the battery, it seems that the Phaeton is satisfied The currents are about 13.8V on the battery, aswell as on the analogue dash readout.
      The problem with the trunk remains though It doesnt respond to either command - press on VW emblem, remote open, or the one in the drivers door. Only the turn signals flash.
      Hi Lukas,
      Does everything else work the way it should? If so, it looks like this is not a battery related problem. Perhaps it is just a matter of synchronizing, or something mechanical in the lock itself. Please take a look at this THREAD.

      Willem

    20. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      02-14-2012 01:43 AM #20
      Quote Originally Posted by laser21 View Post
      Ok, so after charging the battery, it seems that the Phaeton is satisfied The currents are about 13.8V on the battery, aswell as on the analogue dash readout.
      The problem with the trunk remains though It doesnt respond to either command - press on VW emblem, remote open, or the one in the drivers door. Only the turn signals flash. When I open it with the key, and want to close it - no response to the close button.
      I found a thread, where people say, that the trunk can behave strangely when something is not right. I tried all possible combinations, still no luck.

      Any suggestions? Expoman does your trunk work now?

      Thanks
      Glad to hear that mostly your problems are solved.

      Boot lid - yes, it works but it still has it's moments - often I have to restart the car and use the button on the door arm rest to close it because it won't respond to the remote control or pressing the emblem (although a suspicion is that here again the lack of battery power might have been causing this).

      You will find copious amounts of discussion on the boot lid on this forum- good luck!

      Best,
      Steven

    21. Member
      Join Date
      Jul 5th, 2008
      Location
      Strasbourg - France
      Posts
      1,140
      Vehicles
      May 04 V8
      02-14-2012 06:14 PM #21
      Quote Originally Posted by Expoman View Post
      ...often I have to restart the car and use the button on the door arm rest to close it because it won't respond to the remote control or pressing the emblem...
      Steven
      Are you saying that you can close the boot buy pressing on the armrest button ???

      P.

    22. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      03-07-2012 01:14 PM #22
      Hi All,

      It would appear that part of the problem of diagnosing the recent difficulties with my battery has been brain fade of the owner of the car. He can offer some excuses - the period leading up to large events is very intense and it's hard to think of much else but................................

      It struck me today that I recently installed the Solisto MP3 unit in place of my CD Autochanger so I unplugged it last night when I locked the car - result : car opened normally this morning, LH battery not discharged, so QED you might say.

      But then I thought again - there was no problem with this in the period immediately after the Solisto was installed, even I was sufficiently attuned to the new piece of kit being installed that I was monitoring to see if anything odd was happening. And then it struck me - the ProClip.

      One of the features is that instead of plugging the cable into the iPhone every time you get into the car, you plug the cable into the bottom of the Proclip which has a connector that fits into the iPhone itself allowing very easy insertion and removal as well as charging the phone and it is this I am convinced is causing my battery to drain overnight - if it can charge, not can drain is the I see it but I'm sure Willem will have something to say on this.

      So, I am giving the car another night not connected to the Solisto and if it is fine tomorrow, as I expect it to be, I will reconnect the Solisto but without the lead being connected to the ProClip and see how that goes.

      I have however noticed a clunk from the near side rear of the car (RHD) every time I switch off and on and I think this is the intermittent fault with the boot (trunk) picked up on the UK dealers scan (of course it may be nothing to do with it but I feel like I am on a roll!).

      We'll see, she's booked in with the excellent Phaeton technician in my local French dealer next Monday whereupon I hope all will be revealed.

      As ever, I will keep you posted.

      Best,
      Steven

    23. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      03-10-2012 03:34 AM #23
      Doesn't appear to be the Solisto although I will get it and the connection to the ProClip checked - after 48 hours with both disconnected, LH battery still discharged.

      So it's in the hands of the Phateon tech on Monday.

      Best,
      Steven

    24. Member WillemBal's Avatar
      Join Date
      Nov 20th, 2010
      Location
      Putten, Netherlands
      Posts
      736
      Vehicles
      Phaeton 04W12, Crystal Grey & Extended Leather, '03AudiA4 1.8T, '51 BMW R25
      02-12-2012 07:52 PM #24
      It is perhaps interesting to know, that on Phaetons with Diesel engines, the LH and the RH battery are automatically switched in parallel when the temperature drops below -10 ⁰C.

      Willem

    25. Member n968412L's Avatar
      Join Date
      Apr 23rd, 2009
      Location
      Ramsbottom, UK
      Posts
      1,748
      Vehicles
      2008 3.0TDI Phaeton; 2009 1.4 Tiguan; 2005 V10 Phaeton; 1992 Golf Mk 2 Driver 1.8
      02-13-2012 02:50 AM #25
      Quote Originally Posted by WillemBal View Post
      It is perhaps interesting to know, that on Phaetons with Diesel engines, the LH and the RH battery are automatically switched in parallel when the temperature drops below -10 ⁰C.Willem
      Something else marvellous that I didn't know!

    26. Member WillemBal's Avatar
      Join Date
      Nov 20th, 2010
      Location
      Putten, Netherlands
      Posts
      736
      Vehicles
      Phaeton 04W12, Crystal Grey & Extended Leather, '03AudiA4 1.8T, '51 BMW R25
      02-13-2012 06:33 AM #26
      Quote Originally Posted by n968412L View Post
      Of course you're right... but I'm so old that I started driving in the '70s and the vehicles I could afford then all had dynamos...
      The first car I could afford was a ’64 model of DAF 44, the one with the belt transmission (automatic gear system, invented by Van Doorne). Great acceleration, often faster than other 4-cylinder engine cars, although it only had a 2-cylinder boxer motor. Top speed 140 km/h. It had a 6 Volt battery system … with a dynamo. I spent too much time on replacing brushes and regulators.

      Quote Originally Posted by n968412L View Post
      I'm very suspcious. I think it might be damped like the coolant temperature guage is.... although how do you tell as it's not really analogue, is it?
      It is damped, but not that much. It takes less than 5 seconds to read steady after switching on ignition.
      In my own car, I sometimes see it hovering from 13.5 down to 12V with engine running idle. I haven't got the faintest idea what happens then. Increasing the engine RPM brings it back to 13.5 V.

      Where would you pick up and log system volts with VAG-Com??
      Try Address 71: Battery Charger 3D0 915 181 C.
      From the advance measuring blocks (I think), it is Group 1 - Field 2 , Terminal 30 (Comfort battery). There should be a “Current - Term 30 (Battery)” as well. It would be interesting to see what that current is reading. Mine is always zero.

      I've certainly been measuring 11.5V at the battery with a branded digital multimeter,whilst the dash voltmeter is showing 12.5V.
      Interesting. I was pretty sure that the dash volt meter would be a class II device, i.e. 2% of range (+/- 0.3 V). I think it is an analogue instrument, connected to a DAC. This DAC would convert the battery voltage as given by the CAN bus back to an analogue signal.
      An infamous problem of needle type of indicators is the viewing angle. The difference between the viewing angle as is the case when we look at the meter, versus the optimal angle (slightly at the right of the steering wheel) is almost +0.5 Volts!

      . I have not yet ruled out the multimeter.. but as it's showing readings I believe for the conditions.. and it seems to follow the battery volts up to 14.5V when appropriate, I think it's OK.
      I think you mean to say that your multimeter shows the same trend? I.e. reads 11.5V versus 12.5, and 13.5 versus 14.5 on the dash meter? That makes sense. When it is really showing 14.5 on you multimeter, then it would be way too high. To be honest, even the often reported 14 and 14.2 Volts seem to me rather optimistic. The only time that 14.2 Volts is ever reached, would be with an external charger such as the one you have. Smart chargers “measure” the status of the battery prior to charging it. Then they do a bulk charge, then top off the charge up to 14.2 Volts. But in a car battery management system, it cannot work that way, because the many consumers blur prevent an accurate measurement of the charge status of the battery. The float charge principle always limits the charge current to a safe level in order not to damage the battery. So it is only logical that the voltage of a discharged battery cannot be 14.2 V shortly after you have started the engine.
      This gives food to the thought that the dash meters aren’t that accurate as I assumed. My own dash meter usually is hovering around 13.5 and only reaches 14 on long trips.

      I'll keep researching it!
      That’s the spirit!
      It would be a small effort to calibrate (determine the deviation) of the dash voltmeters on a next GTG.

      Willem

    27. Member n968412L's Avatar
      Join Date
      Apr 23rd, 2009
      Location
      Ramsbottom, UK
      Posts
      1,748
      Vehicles
      2008 3.0TDI Phaeton; 2009 1.4 Tiguan; 2005 V10 Phaeton; 1992 Golf Mk 2 Driver 1.8
      02-13-2012 06:59 AM #27
      Quote Originally Posted by WillemBal View Post

      Try Address 71: Battery Charger 3D0 915 181 C.
      From the advance measuring blocks (I think), it is Group 1 - Field 2 , Terminal 30 (Comfort battery). There should be a “Current - Term 30 (Battery)” as well. It would be interesting to see what that current is reading. Mine is always zero.
      I'll look at it first chance I get....


      Quote Originally Posted by WillemBal View Post
      Interesting. I was pretty sure that the dash volt meter would be a class II device, i.e. 2% of range (+/- 0.3 V). I think it is an analogue instrument, connected to a DAC. This DAC would convert the battery voltage as given by the CAN bus back to an analogue signal.
      My assumption too


      Quote Originally Posted by WillemBal View Post
      I think you mean to say that your multimeter shows the same trend? I.e. reads 11.5V versus 12.5, and 13.5 versus 14.5 on the dash meter? That makes sense. When it is really showing 14.5 on you multimeter, then it would be way too high. To be honest, even the often reported 14 and 14.2 Volts seem to me rather optimistic. The only time that 14.2 Volts is ever reached, would be with an external charger such as the one you have. Smart chargers “measure” the status of the battery prior to charging it. Then they do a bulk charge, then top off the charge up to 14.2 Volts. But in a car battery management system, it cannot work that way, because the many consumers blur prevent an accurate measurement of the charge status of the battery. The float charge principle always limits the charge current to a safe level in order not to damage the battery. So it is only logical that the voltage of a discharged battery cannot be 14.2 V shortly after you have started the engine.
      This gives food to the thought that the dash meters aren’t that accurate as I assumed. My own dash meter usually is hovering around 13.5 and only reaches 14 on long trips.
      Needs more explanation (and research) than I have time to do right now. The 14V + was measured during charging from CTEK charger. Will post more in due course....

      Got to go to work now... bit depressing... would rather carry on here....

    28. Member
      Join Date
      May 15th, 2011
      Location
      France
      Posts
      363
      Vehicles
      2004 V10 TDI Phaeton, 2010 Mercedes 350CLS
      02-13-2012 10:43 AM #28
      Mine was just slightly over 14 when viewed slightly from the right - I even gave it a little tap on the glass face like in the old films!

      When I switched on the lights and engaged the full beam, it dropped to 14 dead.

      This has been a very interesting topic (I know Stu, you're right, I must get out more!) it's very good to be able to manage a problem like this by understanding what is going on.

      Given the type of constant consumption the Phaeton has even when standing locked, the lack of use to which my car has been put over the past month, the unusually low temperatures and the considerable time of driving (4 hours) needed to replenish it, I think I have as good as evens a chance that the battery may not need replacing.

      By this time this coming Saturday all will be revealed - how exciting!

      All best,
      Steven

    29. Member WillemBal's Avatar
      Join Date
      Nov 20th, 2010
      Location
      Putten, Netherlands
      Posts
      736
      Vehicles
      Phaeton 04W12, Crystal Grey & Extended Leather, '03AudiA4 1.8T, '51 BMW R25
      02-13-2012 03:12 PM #29
      Quote Originally Posted by Expoman View Post
      Mine was just slightly over 14 when viewed slightly from the right ....
      Centimetres or inches?.....

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •