1999 E39 535i - Batteries keep being killed

Notices
 

Thread: 1999 E39 535i - Batteries keep being killed

Reply to Thread
Results 1 to 6 of 6
  1. 1999 E39 535i - Batteries keep being killed 
    #1
    Bimmer Fan
    Car Details
    Manual_Reversion's Car Details
    Model of Car:
    535i
    Year of Manufacture:
    1999
    Transmission Type:
    Automatic
    Car Body Type:
    Saloon

    Join Date
    Dec 2010
    Location
    Surrey
    Posts
    3
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Good evening!

    Ok chaps first post here and I need your help. I've had a recurring battery problem that has come to a head now and needs to be resolved. It's costing me a fortune getting taxis to work and back.

    My 1999 535i had the original battery for around eight years before it died and I replaced it with another BMW-sourced battery. That one died just outside warranty (1 year I think). I replaced the second battery with a non-BMW one and now that has just died on me after one year. So, I can accept one bad-egg battery (the second BMW one), but two? No, too much of a coincidence; something is killing my bats!

    Current problem sequence of events: Over past couple of weeks car seems barely perceptibly sluggish to fire up (normally practically instant). I didn't do anything about it. After much snow and some days of no use, go to start and “click, click, click”. I fully charge the battery and the car starts; the next morning I go to drive to work and although it turns over, seems not enough to start it.

    So I measured some voltages:

    Fully charged the battery yields 12.4V across its terminals open-circuit which, temperature-adjusted to 0C, seems to me to be fully charged.

    With a cold engine running I measure the alternator output voltage (at the battery terminals):

    Engine idling: 13.95V
    More than idle: 14.00V

    Engine idling under load (lights, heater fan): 13.75V
    Engine more than idle under load: 13.80V

    After (nervously!) driving around doing errands for a couple of hours (leaving the engine running), we have a nice warm engine and, presumably, fully charged battery. The alternator outputs:

    Engine idling: 13.35 – 13.70V (fluctuating)
    More than idle: couldn't measure / no voltage measured!***

    Engine idling under load (lights, heater fan): 12.52V
    Engine more than idle under load: couldn't measure / no voltage measured!***

    *** Despite attempting to measure the voltage across the battery terminals in the normal way, couldn't find a reading. Battery definitely HAD a voltage as it had just started the engine no probs. Tried various different points on terminals but nothing at all. It has always been hard to get a voltage measurement from the battery/alternator. Sometimes it's no problem, can put the probes anywhere on the terminals/connector braces to get reading. Other times you have to hunt for a reading.

    I've not yet measured the current drain when all locked up and 'asleep'.

    Apologies for the epic post, I know this crops up a lot having googled it, but I've come to the end of my diagnostic abilities and would be grateful of help.

    Thanks in advance.
     
     

  2. Remove Advertisements
    BimmerForums.co.uk
    Advertisements
     

  3.  
    #2
    Bimmer Fan
    Car Details
    xXxStKxXx's Car Details
    Model of Car:
    325i
    Year of Manufacture:
    1993
    Transmission Type:
    man
    Car Body Type:
    saloon

    Join Date
    Apr 2009
    Location
    North London
    Posts
    12
    Thanks
    4,432
    Thanked 6,073 Times in 4,855 Posts
    try this to see if you have a parasitic battery drain....
    http://www.wikihow.com/Find-a-Parasitic-Battery-Drain
     
     

  4.  
    #3
    Bimmer Fan
    Car Details
    Manual_Reversion's Car Details
    Model of Car:
    535i
    Year of Manufacture:
    1999
    Transmission Type:
    Automatic
    Car Body Type:
    Saloon

    Join Date
    Dec 2010
    Location
    Surrey
    Posts
    3
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Thank you StK for the info, I will look into it.

    Additional info on my driving:

    Total mileage over three months results in an average of 14 miles per day. Essentially I just use the car for work, which means a 10 mile journey each way, around four days per week.

    So we're not talking 200 mile drives here, but I would have thought (incorrectly?) that a 20 min drive would be sufficient to replace the charge used to start the engine.

    Kind regards.
     
     

  5. Remove Advertisements
    BimmerForums.co.uk
    Advertisements
     

  6.  
    #4
    BFuk Legend
    Car Details
    steve23002's Car Details
    Model of Car:
    530i Sport
    Year of Manufacture:
    2002
    Transmission Type:
    Auto
    Car Body Type:
    Saloon
    steve23002's Avatar
    Join Date
    Nov 2008
    Location
    Buckingham
    Posts
    11,712
    Thanks
    8,589
    Thanked 8,379 Times in 5,803 Posts
    Have a search on the forum for 'hedgehog, fsr and final stage resistor'
    Common fault on E39's are that it fails and allows the fan to run at very low speed which flattens the battery...
     
     

  7.  
    #5
    Bimmer Fan
    Car Details
    Manual_Reversion's Car Details
    Model of Car:
    535i
    Year of Manufacture:
    1999
    Transmission Type:
    Automatic
    Car Body Type:
    Saloon

    Join Date
    Dec 2010
    Location
    Surrey
    Posts
    3
    Thanks
    0
    Thanked 0 Times in 0 Posts
    For the current drain test I unplugged the two lights in the boot and measured 430mA after it had 'gone to sleep'.

    With the ammeter in place I removed the six small fuses one 40 amp fuse individually. None of them made any different to the current draw that remained at 430mA.

    steve23002, thanks for that, will be my next avenue. What fan is it that runs with this fault?

     
     

  8.  
    #6
    BMW Maestro
    Car Details
    mikesmith2's Car Details
    Model of Car:
    520i SE
    Year of Manufacture:
    2002
    Transmission Type:
    Auto
    Car Body Type:
    Touring

    Join Date
    Feb 2009
    Location
    Reading.
    Posts
    540
    Thanks
    50
    Thanked 83 Times in 74 Posts
    It's the heater fan behind the dash.
     
     

  9. The Following User Says Thank You to mikesmith2 For This Useful Post:

    steve23002 (08-12-2010)

Tags for this Thread

View Tag Cloud

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