Electrics Advice needed?

Discussion in 'Motorhome Chat' started by Jifcom, Jan 8, 2013.

  1. Jifcom

    Jifcom Read Only Funster

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    Hi Folks

    I'm after a bit of advice on fitting a Volt/Amp Meter for my 170w solar Panel.
    Attached is a Pic of the basic wiring and in the Blue circle is what I plan?

    Do I attache the wiring and shunt Before the regulator or after? also what size "Shunt" is recommended?
    Please do tell me if this is completely wrong! and if so, let me know how to do it if you can :)

    Regards

    Jon
     

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  2. hilldweller

    hilldweller Funster Life Member

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    After the regulator is more meaningful - the current into the battery rather than current out of the regulator.

    The shunt depends on the meter, they should supply one.

    For volts you also need a wire to negative.
     
  3. Gromett

    Gromett Funster

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    If you put the shunt in either position you won't measure what is going into the battery from the charger. Not sure if you want that or not though.
     
  4. hilldweller

    hilldweller Funster Life Member

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    Well spotted - he needs it needs it in that tiny vertical red to fully monitor the battery state.

    If he buys something like the NASA it should be clear in the instructions and come with the correct shunt ( which I think they put in the negative side ).

    Mind you - "for my solar panel" - was the original spec.
     
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  5. Jaws

    Jaws Funster Life Member

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    As a by the by, a shunt value is actually in Ohms ( resistance ) rather than watts :thumb:
     
  6. pappajohn

    pappajohn Funster Life Member

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    Until you come to buy one then its in amps :Doh:

    NASA BMI web page.....


    BM-1 Battery Monitor
    The BM-1 is designed to monitor performance of 12 volt lead acid battery systems with capacities of up to 600 Amp hours. It is supplied complete with a precision 100 AMP shunt
     
  7. Gromett

    Gromett Funster

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    You are both correct. It is measured in ohms and its capacity is in amps :Rofl1::Rofl1::Rofl1:
     
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  8. Jifcom

    Jifcom Read Only Funster

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    Many thanks guys for all your comments,
    After reading about the NASA BM-1 this looks far better that others I have looked at (Built mainly in china!)

    So after looking on the web site and downloading the installation destruction's and comparing with what I have wiring wise, does the attached now look more like it.

    I have now brought the BM-1 unit
    So hopefully everything willl now go smoothly.

    Regards

    Jon
     

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  9. Jaws

    Jaws Funster Life Member

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    It is a bit hard to see, ( my eyes proly ! ) but it looks like you have a -ve connection going to the ammeter ?

    The ammeter should just be 'across' the shunt, with no -ve connection
     
  10. pappajohn

    pappajohn Funster Life Member

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    red and black are pos and neg volt meter connections...red from battery and black from battery side of shunt
    the white (battery neg side of shunt) and yellow (load side of shunt) are the ammeter connections across the shunt and are correct
     
    Last edited: Jan 8, 2013
  11. Jifcom

    Jifcom Read Only Funster

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    Here is a larger picture and of the NASA wiring diagram, I think I'm correct, but then again, the wife say's I'm always wrong!! :Eek!:
     

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  12. Jifcom

    Jifcom Read Only Funster

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    :thumb: thanks PapaJohn. posted mine before yours showed up.
    Thanks again to all the comments and help, its appreciated.

    Jon
     
  13. pappajohn

    pappajohn Funster Life Member

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    as you.ve seen with the nasa there is so much more to it than an amp/volt meter.

    drain out, charge in, reserve capacity (based on battery ah)

    well worth the money and you can sell your TV to pay for it as you'll be constantly watching the meter and nothing else. :Laughing:
     
  14. Jaws

    Jaws Funster Life Member

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    Told you it was my eyes !!!
     
  15. Jifcom

    Jifcom Read Only Funster

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    TV!!!!!!!!!!!!!!!!!!!!!!!!! whats that!!!
    more like, 100w Valve amp, Garrard 401 Turntable, Ruark floor-mount speakers, 200 Vinyl LPs and still be able to look at the battery Drain :Rofl1:

    (I wish, but the boss says no!!!! :cry:)
    Cheers guys :thanks:
     
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  16. pappajohn

    pappajohn Funster Life Member

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    must admit the wiring colours had me confused until i looked on the NASA website and downloaded the install instructions.
     
  17. Gromett

    Gromett Funster

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    I can confirm that the wiring is correct. That is how I installed my BM-1. Not as good as the Victron monitor but still pretty handy.

    After you connect it you will need to leave it for a couple of hours (with the charger on) for it to get it's barings (bearings?)
     
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