Battery drain

Discussion in 'Motorhome Chat' started by ederland, Jun 19, 2014.

  1. ederland

    ederland Read Only Funster

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    :cry:My starter battery is being drained by .4amps and it is the fridge that is doing the draining. Why does the fridge run off the starter battery ? Is this normal? why not the leisure battery? I have had to get a start from the ferry company the last 3 times .The fridge works perfect, is it a bad earth? I am confused, please help somebody. My van is a Lunar roadstar 780 built 2005.
     
  2. Jimbohorlicks

    Jimbohorlicks Funster

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    Hi
    i don't think that a 0.4 volt drain will reduce your starter battery to such a point that it will not have enough amps to start the vehicle , unless that is the battery is not holding a charge anyway.I assume that the ferry starts your vehicle after the crossing -not before -if that's the case the fridge is not powered by the alternator because the engine is not running. The fridge would be off even though you have selected the 12 v for the fridge whilst you was motoring to the ferry.
    I would have your cab battery checked.

    best of luck:thumb:
     
  3. cmcardle75

    cmcardle75 Read Only Funster

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    It is quite normal for fridge 12V to be off engine battery. This is because it is only used for ignition (negligible usage) or cooling (engine running only). I suspect, though, that the fridge is not the problem, but you are using one of those inaccurate current meters that don't have a proper zero. You probably just have a bad batt
    ery. You'll need a multimeter and someone who knows how to use it to investigate further.
     
  4. sb8263

    sb8263 Funster

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    i always thought the fridge only run when the engine was running,,therefore it wont be on when you are on the ferry,,,,think you need a check on your main battery to see if its holding a charge and check your alternator is charging at the right rate too..
     
  5. tonka

    tonka Funster Life Member

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    Is it an Autotrail?? The system has a drain of .3 amps if you leave the psu switched on .
     
    Last edited: Jun 19, 2014
  6. sb8263

    sb8263 Funster

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    our psu turns off once i start the engine, only comes back on when i press power button and its an Autotrail...
     
  7. TheBig1

    TheBig1 Funster Life Member

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    standard 3 way fridge wiring utilises a relay to prevent the engine battery draining with the engine off. if the fridge is drawing a current on 12v with engine off, check the relay
     
  8. Jaws

    Jaws Funster Life Member

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    As the big 1 says..
    The fridge should draw NOTHING when the engine is not running

    if the fridge is drawing anything then the relay is stuck on


    A bit of maths
    All ball park figures but close enough

    Lets presume you have a fairly large healthy cab battery that is a 100aH

    Lets say once it gets below 20% capacity it will stand no chance of starting the engine
    So you have 80aH to play with. ( unless you have a traction battery in which case you can go much lower.. say down to 10 % :Smile: )

    At a .4 amp drain that battery will be down to below usability after just 8 days of the van sitting.

    If you have an alarm fitted that will also be drawing current too.. So about a week and you aint going nowhere !
     
  9. hilldweller

    hilldweller Funster Life Member

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    What about the interior light.
     
  10. pappajohn

    pappajohn Funster Life Member

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    if the fridge relay, with engine off, had jammed/welded closed you should see a drain of around 10amps from the starter battery.

    thats why it only works with the engine running, otherwise the battery would be completely dead (as in destroyed) in around 8 to 10 hours
     
  11. TheCaller

    TheCaller Funster

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    If it's like mine, the fridge interior light is wired to the leisure battery.
     
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