Connection between Hab. and Vehicle Batteries

Discussion in 'Tech/Mech General' started by emmitdb, Jan 8, 2016.

  1. emmitdb

    emmitdb Funster

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    Following on from Clarky who thought his question "re batteries 'Daft'??? (He obviously doesn't know the definition. There was nothing daft about it)

    I immediately apologise for the following drivel and the length of the post.

    I am confused regarding the relationship between the Vehicle Battery and the pair of batteries I have in the Habitation area.

    I have an X244 Fiat based Hobby. When I bought it we installed a pair of matched 110ahr batteries. Shortly afterwards we installed an 80watt solar panel on the roof and connected it, via a controller to the Hab batteries and for the past 22mths or so everything has worked good.

    In September we embarked on a two month trip to Spain via France and the electrics worked well. On occasions we wilded for several days without going into the Red on the habitation side and, I put the continued good state of the batteries down to a combination of good weather and the Hab batteries being topped up via the alternator when we were on the move. So far, so good.

    We arrived home on November 13th and at that point the vehicle had a rest and was not used.
    I went to the 'van earlier this week and noted that the vehicle battery gauge had slipped down out of the Green into a mediocre state. The Hab. guage was holding up well. As the 'van had been sat on the drive for two months without turning a wheel I was not unduly concerned or worried. I took out the charger from the garage, gave the engine battery 24hrs on charge and the engine battery needle is now well into the Green.

    However, and this is the main thrust of my confusion. I thought that the solar panel would have for the last two months have provided charge to the engine battery whilst at home. Are motorhomes wired up 'Ordinarily' to provide charge from the Habitation side to the Engine side when given juice by the solar panel.

    My other point of confusion stems from the fact that after I had given the engine battery its 24hrs of charge, whilst the engine battery was much 'refreshed', the Hab side didn't appear to have received anything from the process.

    Here's my simple??? question. Ordinarily, are the two batteries linked and can/does the supply of charge be it from the alternator or the solar panel provide charge to the 'opposite batteries.

    See Clarky. I told you your question wasn't daft. I know mine is.
     
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  2. Techno

    Techno Funster Life Member

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    Most often no
    Varies very much depending on you particular electrical system
     
    Last edited: Jan 8, 2016
  3. Techno

    Techno Funster Life Member

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  4. Khizzie

    Khizzie Funster

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    On my Autocruise stargazer I can switch between hab and starter batteries for charging from the built in charger. I thought all mo ho s were the same ..obviously not.
     
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  5. mjltigger

    mjltigger Funster

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    They are all different. The thing that is most usual is that a relay or similar device keeps the batteries disconnected deliberately until your angina is running and the alternator is pumping out sparky juice. At this point the alternator trips the relay and it is then able to provide charge to all of your batteries. There isn't usually any relay in the opposite direction so it doesn't matter how well charged the solar is keeping the hab batteries, the engine battery will continue to be discharged by loads from radios and alarms etc.
     
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  6. Techno

    Techno Funster Life Member

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    Not the same thing.
    OP is referring to maintaining all batteries on solar without hook up.

     
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  7. Khizzie

    Khizzie Funster

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    Oh sorry misunderstood.!! Its an age thing ..
     
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  8. Techno

    Techno Funster Life Member

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    Not at all it's good that you understand your own electrical system (y) surprisingly a lot do not :LOL:
    You probably already know but just be sure you don't have engine battery selected if you're not on hook up or you'll flatten it. The switch not only selects it for charging but also for feeding the habitation
     
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  9. Kool Kroozer

    Kool Kroozer Funster

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    Yes as the Techno man says, we had a battery master fitted to ours so the leisure battery trickle charges the engine battery, same set up as you have with solar on the roof and both always full an ready to go !
     
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  10. andy63

    andy63 Funster

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    Would a good two way voltage sensing relay be another option.. I have a blue sea 120A relay linking the vehicle batteries and leisure batteries.. seems to work well whatever the charging source to either set of batteries..
    Ta Andy.
     
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  11. Khizzie

    Khizzie Funster

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    I was thinking along those lines ,why wouldn't a split charge relay do the job..??
     
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  12. mitzimad

    mitzimad Funster

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    if you have a simple split charge relay system you can use a simple switch anda low ampage fuse to link across the relay then the solar will charge both whilst stationary but you need to switch of before you move or blow the fuse
     
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  13. emmitdb

    emmitdb Funster

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    Can I thank all contributors to this thread. The veil has been lifted from my eyes.
    Obviously Techno, you're the star here, (but you knew that anyway).
    First prize must go to the contribution by MJLTIGGER who in the course of his piece said,
    "the batteries disconnected deliberately until your ANGINA:sick::sick::sick: is running and the alternator is pumping out sparky juice."

    Mate, I have no idea what was going on whilst you were typing this (but I'm glad that our batteries could be also used as a defibbulator) Nice one.:LOL:
     
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  14. eddievanbitz

    eddievanbitz Trader - Funster

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  15. Khizzie

    Khizzie Funster

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    So how do cars tugging caravans charge both batteries without blowing the fuse or switching it off .?? Oohh,! Think I got it wrong again ,we are talking solar panel power....sorry !
     
  16. quickweh

    quickweh Funster

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    This thread has started me thinking about keeping my vehicle battery topped up during wintertime here in the UK.
    Briefly I have no problem in the summer or in Spain in the winter because there is sufficient daylight to keep both leisure and vehicle batteries topped up. Once leisure batteries are topped or on EHU solar output is diverted to the vehicle battery, see pic for wiring diagram. The controller is a Helios Technology unit, Italian origin and no longer in business and no English manual either.
    In winter here I have to run the engine approximately once per week in order to keep the vehicle battery topped up, there is not any "spare" capacity from the solar panel, which does just about keep the leisure batteries topped up.
    If I connect the EHU there is no charge to the vehicle battery.

    I am concerned that (not being an electrician) that duplicating the battery to battery function may damage the solar controller, any ideas or help appreciated.
    I like the CBE controllers so the link Andy posted would be my favoured option and I think would also work with EHU.

    http://www.ebay.co.uk/itm/SOLAR-WIN...0b&clk_rvr_id=964008464402&afsrc=1&rmvSB=true



    scan0001.jpg
     
  17. daveandsan

    daveandsan Funster

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    I have 2 CBE units on my Hobby, had one fitted to keep the engine battery topped up when I had the solar panel fitted and that was fine all last winter. Fitted another CBE unit a couple of months ago to keep the auxiliary battery topped up (Ford Transit) and I am keeping an eye on it to see if the solar panel copes with it this time of year.
     
  18. Techno

    Techno Funster Life Member

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    It is the Vanbitz unit you need. The one I posted won't transfer charge until 13.6 volts has been reached which won't happen in the weather we've had for some time now.
     
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  19. mitzimad

    mitzimad Funster

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    nothing to do with solar would work the same if on ehu caravans are not in use when the engine is running
     
  20. quickweh

    quickweh Funster

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    But would it work with EHU connected? That gives 13.8 to 14.2 volts across the leisure battery. It looks to be a cost effective way of charging the vehicle battery.
     
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