12 volt supply on van or 240 frominverter

Discussion in 'Solar Power' started by SC 05 OUT, Oct 18, 2016.

  1. SC 05 OUT

    SC 05 OUT Funster

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    My type of motor homing will change next year, more off grid than on. With that in mind my motorhome will need better12 volt power, so fitting I’ll start by fitting solar panels, no real problem there, however with 12 volt A/V equipment what’s the better plan, fit an inverter with the correct 240 power to use the appliances ( the inverter itself will be powerd by the solar) or just use the 12 volt lines. I’ve tried in the past using 12 volt to run the TV (which has a 240 brick and a 12 volt input.) but it’s never worked properly, I tried leads both with and without a 12volt stabilizer built in. My sat receiver (Humax freesat recorder) is 240 only at this time but 12 volt ones with power brick inputs are now available.

    The 12 volt line outputs in vans do very a lot depending on battery charge level, and looking at the scematics for the m/h the 12 volt line is only 10amp at best.

    Would it be better to bypass any 12 volt socket outlets and make up a dedicated wired in stabilised power supply for all the A/V stuff with the correct output power tails for TV/sat receiver stuff etc. as long as the power output of the 12 volt line is not exceeded?

    It seems a waist of power to go 12 volt-240volt-12volt. But if it gives a better more stable supply, is it the way to go. Pure sine wave inverters are not overlay expensive now and having 240 “on tap” would have other uses.
     
  2. Stealaway

    Stealaway Funster

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    Last edited: Oct 18, 2016
  3. Robert Clark

    Robert Clark Funster Life Member

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    Have you considered how much 240v power you realistically need?

    What electrical items do you use on EHU that you'd still want to use when elsewhere?
     
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  4. NickNic

    NickNic Funster Life Member

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    I fitted an inverter to ours when we first got it. It's only been used a handful of times.

    TV and satellite are proper 12v ones so not needed for them and we don't use any other 230v appliances.

    I should probably rip it out and save the weight.
     
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  5. SC 05 OUT

    SC 05 OUT Funster

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    coffee maker? no we havent got one of those yet!

    if I go the inverter route I would wire the whole van appart from the the fridge and water heater,
    so a little microwave use, some hairdrying stuff, but mostly chargeing of usual phones/two way radios/ power to the tv /sat box etc, There really not that much differance in money from a small invereter to a 1600watt/2000watt jobbie that would handle it all.

    theres no piont in doing half a job, but if its does the job better, and is needed to do the job in the first place.
     
  6. pappajohn

    pappajohn Funster Life Member

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    Sorry to disappoint but you ain't running a 1600w inverter off solar.
    If you use it's full output you still need 133 amps/hour....1/4hr use = 34amps, plus conversion losses, out of your batteries and solar will struggle putting that back
     
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  7. Robert Clark

    Robert Clark Funster Life Member

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    A travel hairdryer is likely to use 1200w, likewise as Nespresso machine uses 1400w - so a 2000w (2kw) would probably cope with most needs, but you need to plan how much stuff you have on in one go.

    We've also got a portable washing machine with spin dryer - only cost £70 new and paid for itself in no time compared with campsite laundromat fees.
     
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  8. Robert Clark

    Robert Clark Funster Life Member

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    From memory Phil previously mentioned getting a B2B charger too as well as uprating his batteries
     
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  9. pappajohn

    pappajohn Funster Life Member

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    If, as you state, you will wire the whole van except fridge, water heater AND CHARGER to the inverter you won't be able to use hook up at all unless you also fit a switching device to select inverter or mains.
     
  10. SC 05 OUT

    SC 05 OUT Funster

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    I was thinking of only occasional use anywhere near full power output, Im thinking the more power there is to availble is better,
    the microwave and hairdryer usage would be minimal its just just the A/V stuff that would be on constantly, sometimes recording when out. its just that that 12 volt line can fluctuate so much due to the batter voltage level, it would be differant line of stability

    I was also thinking of 2 or 3 100watt pannal for charging, is that not enought to keep the 2 X 110 amp batteies power up then?
     
  11. SC 05 OUT

    SC 05 OUT Funster

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    yes I do realise that some sort of changeover relay system would be need to do this, and I as I have said IF if an inverter would be a better power sorce for a/v then 12 volt from the line output them perhaps its the way to go.
     
  12. SC 05 OUT

    SC 05 OUT Funster

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    yes and of and the charger, Id not so much as forgoton that as it just slipped my ( failing) memory.
     
  13. Robert Clark

    Robert Clark Funster Life Member

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    Sorry @pappajohn but that's exactly how our Victron inverter / charger works.
    On batteries it's a 2kw inverter, powering all 240v sockets.
    On EHU it switches over to charge mode and cuts in if the EHU power drops out.
    Totally automatic and instant
    No switches -No hassle
     
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