Notices
 
 

  

User Tag List

Thread: Low battery warning

Page 3 of 3 FirstFirst 123
Results 21 to 25 of 25
  1. Re: Low battery warning 
    #21
    Join Date
    Mar 2013
    Location
    Brightlingsea
    Posts
    69
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    8 Post(s)
    Quote Originally Posted by user name View Post
    If you want to picky you will find it was developed FOR the military it will be a cold day in hell when the military starts inventing batteries. I was trying to point out they are different that's all.
    ***? You said "Mike, AGM is not lead acid", so I said "Oh yes it is" (which it is) with a smiley, and pointed out why. I haven't claimed credit for anything. No I'm not a yank and I made no comments about who invented it or why.

    Alternator charging should be around 14.4 so if your car Alternator is only charging at 12.6 you have your culprit.
    I had the same thought as you about a charging problem. When the battery was down at 11.8V I monitored the voltage with the engine running after a jump start (jump battery now disconnected), it was showing around 12.5-12.6V (more revs made no difference) which is nowhere near enough to properly charge the battery - so that point I did suspect the alternator/charging system. However after charging the battery and starting the engine from it unassisted the voltage with the engine running was showing 14.8. I wonder whether the charging system has some intelligence built in such that if the battery is really low it does some sort of soft-start on the charging, and I just didn't monitor it for long enough when it was showing 12.6V.
     
    0 0 0
     

  2. Re: Low battery warning 
    #22
    Join Date
    Mar 2021
    Location
    Ripon
    Posts
    19
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    4 Post(s)
    Quote Originally Posted by MikeBz View Post
    That's useful. Just a minor quibble, " if its a bigger spec it wont hurt the new battery, it just wont charge it up to full capacity" - the best way to damage a lead acid battery is to regularly fail to fully charge it. In this instance I suspect that all will happen is its capacity will gradually reduce to the meet what the charger is expecting so no real harm done.

    I have suspicions about the state of the battery in my Dec '19 Passat. A couple of weeks a ago I had a week of lots of driving (a couple of 200+ mile runs, and 20-40 most other days), then a week later the car refused to start because the battery was too low. Jump started it and went for a drive, 10 mins later tried to restart it - refused. Jump started it again to get it home (battery was at 11.8V, not good) and then put the battery charger on for 24 hours after which it started. I've always had suspicions because unlike the previous 2 Passats, where the stop-start system stopped the engine almost every time you came to a stop, on this one it hardly ever stops it - even after a 4 hour daylight drive with no air-con etc. you can come to a stop and the A symbol on the dash has the line through it meaning that it doesn't want to do it for some reason (e.g. battery too low). On the very rare occasion that it does stop the engine it generally restarts it after anywhere between 5 and 15 seconds. Maybe the battery has always been slightly dodgy.

    Car is still under warranty so it's booked in to a VW dealer for a battery test next week.
    I had the same issues and car went into VW for a battery test. This is a binary test (only shows pass or fail) and they needed the car overnight. The problem persisted and I checked the alternator which as Ok, so I began to think it might be a parasitic drain. Long story short, replaced EFB with an AGM battery and it all seems Ok so far.

    VW batteries have a 5 year warranty. If VW say battery is good, then suggest they carry out a parasitic drain test and check alternator.
     
    0 1 0
     

  3. Re: Low battery warning 
    #23
    Join Date
    Mar 2013
    Location
    Brightlingsea
    Posts
    69
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    8 Post(s)
    VW service centre had the car for 90 minutes and say they checked everything out - all OK except the battery which has been replaced under warranty. Drove for about an hour afterwards and put the meter on the battery - just under 12.6V with and without the engine running. So that leaves me still suspicious of the charging system, but I note many threads on other forums which talk about the charging system aiming to keep the battery SoC between 50 and 80% charged to save fuel (by not charging it to 100%). It might save a few drops of fuel but it will shorten the battery life - this isn't progress... Lots of reports of premature EFB battery failures in VAG cars on other forums.
     
    0 0 0
     

  4. Re: Low battery warning 
    #24
    Join Date
    Mar 2021
    Location
    Ripon
    Posts
    19
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    4 Post(s)
    Quote Originally Posted by MikeBz View Post
    VW service centre had the car for 90 minutes and say they checked everything out - all OK except the battery which has been replaced under warranty. Drove for about an hour afterwards and put the meter on the battery - just under 12.6V with and without the engine running. So that leaves me still suspicious of the charging system, but I note many threads on other forums which talk about the charging system aiming to keep the battery SoC between 50 and 80% charged to save fuel (by not charging it to 100%). It might save a few drops of fuel but it will shorten the battery life - this isn't progress... Lots of reports of premature EFB battery failures in VAG cars on other forums.
    Was the replacement AGM for AGM or EFB for EFB?
     
    0 0 0
     

  5. Re: Low battery warning 
    #25
    Join Date
    Mar 2013
    Location
    Brightlingsea
    Posts
    69
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    8 Post(s)
    Quote Originally Posted by Mittens247 View Post
    Was the replacement AGM for AGM or EFB for EFB?
    EFB for EFB - Moll, same as the faulty one. I see from other forums that there was a bad batch of Moll batteries a few years ago - it seemed to pre-date my car although I guess its possible it was from the batch. I didn't have to mention 'warranty', they just told me what they'd found and handed me the key.
     
    0 0 0
     

Page 3 of 3 FirstFirst 123

Similar Threads

  1. Low Battery Warning!
    By Richmix in forum Audi A4 - B8 Forum - 2008 - 2015
    Replies: 26
    Last Post: 21-04-2018, 09:44 AM
  2. Battery Warning
    By pxr5 in forum Audi A6 - C6 Forum - 2005 - 2010
    Replies: 8
    Last Post: 17-08-2012, 07:56 PM
  3. Please Help 2003 A4 1.9 130 battery warning
    By A7788 in forum Audi A4 - B6 Forum - 2002 - 2005
    Replies: 0
    Last Post: 01-08-2012, 10:03 AM
  4. Battery warning light
    By Token in forum Beetle 2000-
    Replies: 1
    Last Post: 28-11-2009, 02:53 PM
  5. Battery warning light????
    By vwluke in forum Touran - Sharan - Caravelle
    Replies: 5
    Last Post: 22-11-2009, 10:03 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


 



  


Disclaimer: VW Audi Forum is an "independant enthusiast website", administered in line with guidelines supplied by VAG in the UK, and is in no way related to any of the Worldwide Volkswagen,Audi,Seat,Skoda,Bentley,Bugatti,Porsche or Lamborghini group of Companies. For official up to date information on any of there vehicles, please visit the official websites. Any comments made throughout this website, are the views of the respective poster, and in no way represent the views of the VW Audi Forum Administration, or the worldwide Volkswagen & Audi Group of companies.


VW Audi Forum do not vet and are not responsible for any information which is posted in this forum. All content is viewed and used by you at your own risk and we do not warrant the accuracy or reliability of any of the information.


Copyright: Certain "words", "phrases" and "Images" used on this website by the Administration are "Copyright" of Volkswagen GB, Volkswagen AG (Germany), Audi GB, Audi AG (Germany), Volkswagen Motorsport GB, Volkswagen Motorsport AG (Germany), Audi Motorsport AG (Germany), Volkswagen Racing GB, Bentley, Bugatti, Porsche and Lamborghini. No image can be replicated by anyone WITHOUT the relevant Companies written permission.


All trademarks and copyrights remain property of their respective owners.

No part of the VW Audi Forum website or forum may be reproduced without written permission from the site administration


PLEASE NOTE - PERSONAL ABUSE, ABUSE AGAINST THIS OR ANY OTHER WEBSITE OR ANY COMPANY WILL NOT BE TOLERATED. OFFENDERS WILL BE MODERATED OR EVEN BANNED.


This website and forum are best viewed at a minimum resolution of 1024 by 768.



  



- VW AUDI Forum - The #1 Volkswagen (VW) Group Forum - Volkswagen (VW) - Audi - Seat - Skoda - Bentley - Bugatti - Lamborghini - Porsche - Scania - MAN - Ducatti - VW Audi Forum -


- www.vwaudiforum.co.uk - www.vwaudiforum.co.uk -