W209 key fob battery draining

Discussion in 'Electronics' started by Brutu583, Mar 26, 2014.

  1. Brutu583

    Brutu583 New Member

    Messages:
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    Joined:
    Mar 14, 2014
    Car:
    2002 W209 CLK240
    Hi Guys,

    I've got a weird problem with my key fob. The batteries are draining after just over a week. Could there be a short?
     
  2. Dec

    Dec Hardcore MB Enthusiast

    Messages:
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    Car:
    C180,A. September '97 48k
    These remotes fobs transmit on Infrared and an RF signal (Radio Frequency)
    If a button were stuck ON /shorted then that could drain the remote fob battery/s
    There is a test for an infrared remote fob through a digital camera as depicted in the video below.

    [YOUTUBE]zQhwvjw29NA[/YOUTUBE]

    There is also a test for RF in the picture below, not necessarily proof of the presence an actual RF signal but its presence would confirm consumption of power via a remote fob button.

    The RF sounds like this here… http://homepage.eircom.net/~decdec/fobsound.wma

    [​IMG]

    If either signal is detected while any of the remote fobs buttons ARE NOT being intentionally depressed then that’s the only way you could detect a drain in a remote fob, without special equipment.

    Otherwise, are the correct and good quality batteries being fitted into the remote…OR…is it that it’s the car batteries that’s being drained and the remote fob batteries are not the problem.

    Dec
     
  3. OP
    OP
    Brutu583

    Brutu583 New Member

    Messages:
    22
    Joined:
    Mar 14, 2014
    Car:
    2002 W209 CLK240
    What video?
     
  4. OP
    OP
    Brutu583

    Brutu583 New Member

    Messages:
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    Joined:
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    Car:
    2002 W209 CLK240
    Just tried checking the ir beam with a camera. No buttons are stuck :/
     
  5. Dec

    Dec Hardcore MB Enthusiast

    Messages:
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    Is there not a utube video fornenst you in post 2 above, perhaps the computer you are using is blocked from accessing utube, try this link here… Key fob IR test - YouTube

    How did you get on with the Radio (RF) test?

    Dec
     
  6. KillerHERTZ

    KillerHERTZ Administrator Staff Member

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    Location:
    Cambridge
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    CLS55 AMG
    Cheap batteries? Keys in pocket & button being constantly pressed?
     
  7. OP
    OP
    Brutu583

    Brutu583 New Member

    Messages:
    22
    Joined:
    Mar 14, 2014
    Car:
    2002 W209 CLK240
    Not cheap batteries. Tried Duracell,maxell,energiser and Varta lithiums. The pocket thing is doubtful coz when I use the spare it doesn't happen. What it could be is the pins in the battery compartment might be shorting the key. So I switched compartments with the spare and taped a new set of batteries to the key just incase they die whilst I'm out. If that doesn't work, I think I need to order a new one :/
     

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