Engine battery charging from EHU

Discussion in 'Tech/Mech General' started by Ridgeway, Feb 23, 2014.

  1. Ridgeway

    Ridgeway Funster

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    I'd assumed that in order to charge the engine battery from the EHU you'd need to install something like a battery master.

    Now I may have got something wrong but when I brought the camper around to the house last night to charge the hab battery on EHU at the house I noticed what I thought was the engine battery also getting charged. I wasn't 100% sure so I put a meter over the engine battery and sure enough when the EHU was live the reading shot up from 13v to 13.8v and also I could see that this battery had been charged over night as it was connected to the EHU.

    Is this normal on a non modified icecream van ?
     
  2. Phill D

    Phill D

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    normal on many many motorhomes:thumb:
     
  3. Ridgeway

    Ridgeway Funster

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    ok good news, thought the Italians had been up to tricks:Eek!:
     
  4. Ridgeway

    Ridgeway Funster

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    So I assume then that there is no charging off EHU and thats why you need a battery master ?
     
  5. JeanLuc

    JeanLuc Funster

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    Not unless you have a solar panel and a dual-battery regulator that can charge both starter and hab batteries.

    Be careful before fitting a battery master as I understand that some charging systems that automatically charge both habitation and starter batteries, may not like having a battery master as well.
    What setup do you have?
     
  6. Ridgeway

    Ridgeway Funster

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    Thanks, will have to check on the existing set up.
     
  7. eddievanbitz

    eddievanbitz Trader - Funster

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    Battery Master can only operate if the bias is 0.75 VDC. If a dual charge set up is present, the batteries will be in parallel, so the voltage in both batteries would be the same so Battery Master would be open circuit, not able to affect anything or be detectable to any other charging device.

    A bit like a solar panel regulator, when the engine is running

    Eddie
     
  8. Ridgeway

    Ridgeway Funster

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    So in other words it would be OK to install a BM and it would be beneficial ?
     
  9. eddievanbitz

    eddievanbitz Trader - Funster

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    Yes, and it's only fair to mention that there are cheaper ( inferior) copies available ( not potted/vibration proof/waterproof/built in fusing/short circuit protection etc)

    However if you want the real deal they are available in Jim's shop http://shop.motorhomefun.co.uk/product/battery-master/
     
  10. Ridgeway

    Ridgeway Funster

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    Thank you Eddie.

    So it's true that Jim's black box is the same as yours:BigGrin:

    Are you both peroxide blondes as well:Rofl1:
     
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  11. eddievanbitz

    eddievanbitz Trader - Funster

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    Hair is an issue with us both lol
     
  12. peterc10

    peterc10 Funster

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    I have a Schaudt Electroblock charger in my Adria which keeps both leisure and engine batteries topped up when I am on EHU (and also when and if I install a solar panel). I am struggling to see what advantage I would gain from using a BM to do what I think the Schaudt already does. Or am I missing something?
     
  13. eddievanbitz

    eddievanbitz Trader - Funster

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    No your not missing anything. If you keep your van plugged into the mains, the Electroblok will trickle charge your engine batteries. Most systems don't.

    Where you'll loose out is when not on mains, the engine battery will be discharged due to the quiescent drain. Memories from clocks and radio's, immobilisers, ECU's security devices and the like. With Battery Master the load will be automatically share the load between the engine and the leisure batteries, significantly extending time you can leave the motorhome and still be able to start it.

    If you do install a panel and if you do decide to connect it to the existing system you will have a lesser system. You would be better to connect the solar panel to a good quality regulator which offers MPPT and then connect that MPPT regulator to the leisure batteries with the appropriate cable, taking into account cable length (voltage drop) the out put of the panel and whether your connecting to both banks of batteries

    I hope that helps

    Eddie
     
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