Inverter problems, ideas please

Discussion in 'Tech/Mech General' started by lesleyjean, Apr 15, 2013.

  1. lesleyjean

    lesleyjean Funster

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    Normally when we are away in the motorhome we can plug laptop into the inverter and laptop will remain fully charged. Also other items like phone, toothbrush etc can be charged whilst driving.

    Our last holiday the inverter only had available power when the engine was switched off and therefore did not keep laptop charged.:RollEyes:

    Has anyone got any ideas why it suddenly only works when engine is switched off.

    We are baffled, but would like to sort it out before our next trip.

    All advice welcome.:BigGrin:

    Thanks guys
     
  2. Traveller_HA5_3DOM

    Traveller_HA5_3DOM Read Only Funster

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    It is quite normal to have the Inverter connected to the leisure battery. The Red and Black thick leads normally go straight to the leisure battery with a suitable fuse on the Red side.
    The symptoms you describe would be in line with your inverter being connected through the relay that turns off most of the power to the domestic leisure side of the van when the ignition is switched on.
    If you do attempt to correct the way it is wired yourself be aware that DC voltage of only 12 volts is capable of welding steel if you should accidentally short out the battery with those thick wires. Seek more advice if you are not competent with DC wiring.
     
  3. Larby

    Larby Funster

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    I may be asking a silly question but is the battery flat or has it got a bad connection? When running there will be a supply which the inverter will take.
    Put a voltmeter across across the terminals?
     
  4. lesleyjean

    lesleyjean Funster

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    The thing is, it worked fine for 4 years and now suddenly only works when the ignition is switched off.

    So any ideas what could have changed?
     
  5. lesleyjean

    lesleyjean Funster

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    I will check this when I get home
     
  6. Reallyretired

    Reallyretired Funster

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    If it works when the engine is not running then it's not likely to be the battery. It may however be the alternator is producing a voltage outside the range the inverter is designed to work on, so it may be shutting itself down to protect it's circuitry. I would check the voltage with the engine running and check it's not significantly more than around 14.5v.
     
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  7. hilldweller

    hilldweller Funster Life Member

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    This sounds a good call, but you need to have the inverter loading the battery to be sure. If it's a bad contact between the battery clip and the battery it might be good enough to show good on a voltmeter and even light LED lamps. So put you lappy on charge with it turned on. Then measure.

    Turning on everything you have connected to the leisure battery, engine off, might also give you a visual clue.
     
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  8. jonandshell

    jonandshell Funster

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    Many inverters are specced between 10 and 15 volts.

    There is a possibilty you could have a faulty alternator regulator amd exceeding the inverter's limit, causing it to cut out with an overvoltage fault.

    You will need to check your charging voltage with a multimeter when the engine is being revved up.:Smile:
     
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  9. pappajohn

    pappajohn Funster Life Member

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    I agree....over-voltage caused by a faulty alternator.
    turn off the engine and the higher battery voltage soon drops to normal

    there's no other reason i can think of.
     
  10. lesleyjean

    lesleyjean Funster

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    So do I need a new alternator do you think?
     
  11. hilldweller

    hilldweller Funster Life Member

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    What's the saying "fools seldom differ" ?

    It works when the engine is NOT running. We should learn to read.
     
  12. hilldweller

    hilldweller Funster Life Member

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    First check the voltage

    1 - Engine not running - expect 12.5 ish

    2 - Engine running for some minutes. Not more than 14.5
     
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  13. lesleyjean

    lesleyjean Funster

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    I am so stupid.

    I bought two new leisure batteries today and fitted them under passenger seat. Inverter still didn't work with engine running.

    I am not very good with them meter thingies, but will have a look tomorrow now.

    Just been looking at prices of alternators:Eeek::Eeek:

    Think I will sell the motorhome:BigGrin:
     
  14. pappajohn

    pappajohn Funster Life Member

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    as Brian said.....but dont check immediately after turning off the engine.

    either wait an hour or turn on the headlamps or put the heater fan on full for a couple of minutes first (if it needs ignition on thats fine) to remove the excess battery voltage, then turn off and check battery voltage.

    as long as the voltage is a bit lower than when running the engine that's all you need.
     
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  15. pappajohn

    pappajohn Funster Life Member

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    cant be worse than the one for my car Lesley........main dealer price £475 :cry:

    even running on leisure batteries it could still be over-voltage if the alternator is faulty
     
    Last edited: Apr 15, 2013
  16. lesleyjean

    lesleyjean Funster

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    :Eeek::Eeek::Eeek:
     
  17. Reallyretired

    Reallyretired Funster

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    Please, please measure the voltages. You have replaced the batteries which must have cost a bit and there was really nothing to show that there was anything wrong with them in the first place. Please don't replace the alternator without finding out if there's anything wrong with that first. I hate to see people waste money that could be better spent on buying me a drink :Laughing:

    You can get a digital multimeter for about a tenner which will pay for itself many times over.

    If you really don't feel you can measure the voltage then Wildman is near you, perhaps a run up to Rogers if he's at home. Jaydee is also down in your area (same county anyway).

    Roger is running a 12v seminar at his August rally if you can make it.
     
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  18. lesleyjean

    lesleyjean Funster

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    Roger:BigGrin:

    If you are reading this:BigGrin::BigGrin::Laughing:

    When can I pop around to The Lazy Buzzard for you to quickly:Blush:Check my alternator and battery voltage.:Rofl1:
     
  19. hilldweller

    hilldweller Funster Life Member

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    This is getting a bit interesting.

    Why isn't wildman sorting this, a ten minute job for him.

    Anyway, can you see the alternator and the two thick 12V wires powering it ?

    Can you see where they connect ?

    Can you show us any pics ?
     
  20. Wildman

    Wildman Read Only Funster

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    Well Lesley popped around and I got down to it, then eventually got a meter out and took some measurements, using my digital cigar socket voltmeter the engine battery was reading 15.4V oops, then dropped to 12.7V, ran the engine and it was 14.4V
    checked leisure batteries 15.4 Volts.
    Solar panel regulator, voltage in 15.4V voltage out 15.4V now that seems a bit over the top and would cause an over voltage regulator in the inverter to trip.
    I disconnected the steca and after a while got a true battery reading of around 13v (leisure batteries) the inverter still works with the engine off but not when it is running so I am a little mystified, alternator charging normally. Is there a reset procedure for the Steca pr 1010. (Though that will not now affect the inverter) The spec appears to indicate it is protected against battery removal (But maybe not in bright sunlight). Ideas please.
     
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