Battery monitors...

Discussion in 'Motorhome Chat' started by Charlie, Nov 11, 2015.

  1. Charlie

    Charlie Funster

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    On the sergeant control panel in our MH there is a button we can press that shows the remaining charge left in the vehicle battery or the leisure battery .. But it's basic to say the least. Not sure I would trust it to be honest.

    So I'm thinking along the lines of either a battery monitor for just the leisure battery or one for each battery.

    How easy are these things to wire ? Is it just a simple wire to each terminal on the battery up to the monitor display or is there more to it ?

    Cheers
     
  2. Geordies

    Geordies Funster

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    As you say, two wires from simple digital voltmeter one to each terminal, but you want a very low current fuse in the positive line right on the terminal
     
  3. pappajohn

    pappajohn Funster Life Member

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    Monitors such as the NASA BM1 require a 100amp shunt on the battery but it still only calculates from a known capacity and voltage in much the same way as the sergeant unit.
    The difference being it will show you in real time what current (amps) is being drawn and replaced at any give time.
     
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  4. Don Quixote

    Don Quixote Funster

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  5. pappajohn

    pappajohn Funster Life Member

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  6. andy63

    andy63 Funster

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    The Stirling monitor shown in the first photo..would be capable of doing what you want... you would need a shunt for each battery bank you want to monitor for current and the amp hour function is only available on one circuit. ...There is no estimating and inputting the battery bank capacity... simply start off from fully charged batteries and a zero reading on the amp hr's.
    20151112_122407.jpg

    I'll add a photo of a Chinese version at a fraction of the cost but not got round to playing with it yet..The instructions for setting it up were a bit more involved and put me off :).. With that one you might need one for each battery bank... can't remember...
    Some say they are unnecessary,but I find the Stirling one great..and judging by the number of people who keep asking what their electrical usage and state is ,a worthwhile device if you have the money to get and fit one..
    Ta Andy.
    20151112_122620.jpg
     
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  7. Charlie

    Charlie Funster

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    The Nasa is the one I like the look of. I saw it has a "shunt" but a bit unsure what it does or how it would wire in which is why I asked the question above.

    What is this shunt and what does it do ?

    Would I need one panel for the leisure battery and another for the vehicle battery ?

    Is the Nasa BM1 a surface mount panel ? It looks in the pictures like a thin panel and that would suit what I have in mind..

    Thanks !
     
  8. JeanLuc

    JeanLuc Funster

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  9. Taran_Las

    Taran_Las Funster

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  10. andy63

    andy63 Funster

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    the shunt is just a very low known resistance which is wired in series with the battery bank in quite often either the positive or negative side.. the wires (light duty) off each end of the shunt measure the small volt drop for a given current and displays that current flow on the panel..
    not sure whether the Nasa one has the facility for more than one shunt to be connected but know the stirling one in the photo above has..
    ta andy
     
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  11. Don Quixote

    Don Quixote Funster

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  12. manda3000gt

    manda3000gt Funster

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    The NASA will show habitation battery bank and engine battery
     
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  13. Lenny HB

    Lenny HB Funster

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    I think you will find the factory settings as it comes work fine. If you want to make wiring easy they now do a wireless add on for about 20 quid so you don't need to run any wires from the shunt to the meter.
     
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  14. Charlie

    Charlie Funster

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    The victron as far as I can work out is not a flat panel.. For the installation I plan to do I need a flat panel that doesent stick out far.

    Thanks.
     
  15. Don Quixote

    Don Quixote Funster

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    600s.jpg
     
  16. Charlie

    Charlie Funster

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    Is that display sunk in ? I can't cut into the cabinet where I would like to fit the panel...
     
  17. Don Quixote

    Don Quixote Funster

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    No you will need to cut no matter what monitoring system you fit.
    BMV_monitor_rear.jpg
     
  18. Charlie

    Charlie Funster

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    I think the Nasa one if a flat panel... If it's not the Nasa compact is. I can't cut behind where I want to mount it so its s flat one or I have to start again.
     
  19. Don Quixote

    Don Quixote Funster

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    Looks like a nice unit, but still have to hide that wire:
     
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  20. Charlie

    Charlie Funster

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    The wire is no problem.. Cutting the panel is not possible.. I think the standard Nasa BM1 is also s flat panel.. Flatter in fact than the one in your link..

    Thanks !
     
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