Second Leisure Battery

Discussion in 'Motorhome Chat' started by Yorick, Sep 3, 2014.

  1. Yorick

    Yorick Funster

    Joined:
    Oct 1, 2013
    Messages:
    3,925
    Likes Received:
    5,667
    Location:
    Lanzarote
    Yesterday I was talking to a local man about fitting a second leisure battery to my Transit based camper.

    I also want him to fit a split relay thingy, but he said the alternator wouldn't be big enough to charge both leisure batteries.

    He suggested having 2 seperate batteries. One charged from van and one from EHU.

    is he talking bollox?
     
  2. Yorick

    Yorick Funster

    Joined:
    Oct 1, 2013
    Messages:
    3,925
    Likes Received:
    5,667
    Location:
    Lanzarote
    And a second question. Many moons ago the van battery flattened as we left the fridge on while not travelling. Sadly the leisure battery was not man enough to jump it off.

    would this addition of a second battery provide the extra needed power to start the van in an emergency?

    Thanks.
     
  3. Daz n Tina

    Daz n Tina Funster

    Joined:
    Jan 8, 2014
    Messages:
    736
    Likes Received:
    1,835
    Location:
    Emsworth
    with regards to the fridge the van battery should not discharge as there should be a in line relay which only allows power to the fridge when the engine is running and shuts off when the engine stops. My van has two leisure batteries and is charged from the alternator or ehu - but in fairness i dont know what amps my alternator kicks out.
     
  4. JJ

    JJ Funster

    Joined:
    May 1, 2008
    Messages:
    14,546
    Likes Received:
    25,668
    Location:
    Quinta Majay, Pinheiro Bordalo, Portugal
    Don't listen to me because others know far more but...

    Your alternator can charge 2 leisure batteries but will take longer to fill them up.

    Unless it is a compressor fridge then the fridge will quickly flatten your batteries.

    The usual set up is you can only work your fridge on 12 volts when the engine is running (the fridge relay knows when the engine is running and connects the fridge).

    The second leisure battery won't help very much with jump starting unless the connecting wires are nice and fat.

    JJ :cool:
     
  5. DonA4000

    DonA4000 Funster

    Joined:
    Jul 23, 2013
    Messages:
    289
    Likes Received:
    164
    Location:
    Scotland
    What age is your transit? You should be able to find out what power output your alternator has!
     
  6. Yorick

    Yorick Funster

    Joined:
    Oct 1, 2013
    Messages:
    3,925
    Likes Received:
    5,667
    Location:
    Lanzarote
    Thanks. I forgot to mention that there is no fridge relay. Yet. That's next on list.
     
  7. Wissel

    Wissel Read Only Funster

    Joined:
    Sep 16, 2013
    Messages:
    301
    Likes Received:
    323
    Location:
    Cornwall
    Yes he is (probably).

    I have a few minutes free, want a drawing of exactly what you need?
     
  8. Wissel

    Wissel Read Only Funster

    Joined:
    Sep 16, 2013
    Messages:
    301
    Likes Received:
    323
    Location:
    Cornwall
    Was bored so did a drawing anyway :)

    [​IMG]
    This will give you a split charger for your leisure batteries and power your fridge correctly on 12v (so it just comes on when engine is running).

    It will also allow you to jump the starter battery from the leisure batteries by by-passing the relay (I have a similar system fitted in my own van).

    Because of the current needed to jump start you will need 25mm cable where shown.

    Hope this helps.
     
    • Like Like x 3
  9. Yorick

    Yorick Funster

    Joined:
    Oct 1, 2013
    Messages:
    3,925
    Likes Received:
    5,667
    Location:
    Lanzarote
    Cheers Wissel
     
  10. Wildbill

    Wildbill Funster

    Joined:
    Nov 18, 2011
    Messages:
    7,076
    Likes Received:
    12,056
    Location:
    Goole funster top up and elsan point
  11. Wissel

    Wissel Read Only Funster

    Joined:
    Sep 16, 2013
    Messages:
    301
    Likes Received:
    323
    Location:
    Cornwall
    Assuming you already have two batteries , so want four, it's worth connecting them in a way that charges and discharges them equally. I have four in my own build and this is how they are connected:
    [​IMG]
    What this does is splits the batteries into two banks diagonally, then joins the two banks diagonally. Looks complicated but it's just one extra cable.

    I spent ages (mainly on marine forums) working out the best way of doing this in a motorhome. If interested this is my whole charging system:

    [​IMG]
    (although no Smartcom now as I went with a compressor fridge)
     
    • Like Like x 6
  12. Wildbill

    Wildbill Funster

    Joined:
    Nov 18, 2011
    Messages:
    7,076
    Likes Received:
    12,056
    Location:
    Goole funster top up and elsan point
  13. Don Quixote

    Don Quixote Funster

    Joined:
    Jul 29, 2012
    Messages:
    2,498
    Likes Received:
    3,696
    Location:
    Lost in La Mancha, Spain
  14. WOOOODENTOP

    WOOOODENTOP Funster

    Joined:
    Apr 19, 2014
    Messages:
    79
    Likes Received:
    44
    Location:
    CHESHIRE
    Fit a solar panel
     
  15. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,461
    Likes Received:
    16,889
    Location:
    YO11 2BD
    The simple answer is yes, he's talking bollox.

    Many folks have 3 or even 4 batteries connected together as one and they charge ok.
     
  16. Yorick

    Yorick Funster

    Joined:
    Oct 1, 2013
    Messages:
    3,925
    Likes Received:
    5,667
    Location:
    Lanzarote
    Yes. I'm gonna fit one. But still would like answers to this please.
     
  17. tonyidle

    tonyidle Funster

    Joined:
    Aug 6, 2013
    Messages:
    2,867
    Likes Received:
    2,686
    Location:
    Kendal, Cumbria
    Absolutely correct. Alternator size is irrelevant and it will perform exactly as JJ says.
     
  18. Chris

    Chris Funster Life Member

    Joined:
    May 5, 2010
    Messages:
    16,434
    Likes Received:
    34,468
    Location:
    kent
    Thanks.

    I think I might have a crack at that at the weekend.

    Looks easy peasy to a man of my abilities.

    Anyone got any idea of the value of a 2013 burnt out Autotrail Scout?
     
    • Like Like x 2
  19. TheCaller

    TheCaller Funster

    Joined:
    Sep 23, 2013
    Messages:
    1,818
    Likes Received:
    2,154
    Location:
    Lincs
    I don't think you can better this for a bare van conversion. The only thing I would do differently would be to feed at least one fuse box from the 12V 80A voltage regulated Consumer output on the SMARTPASS, rather than direct from the batteries. I would then put anything likely to suffer if supplied with the 14+V charging voltages on this fuse box. When in 'Recover' mode, the MXS 25 can be pushing out over 15V. This output also protects the batteries from over-discharge, because it shuts off if the batteries drop to critical levels.

    I can't find the exact voltage that the Consumer output is regulated at, but I suspect it is limited to 13.5V max, because that's what CTEK mains chargers provide when in 'power supply' mode.
     
  20. Wildman

    Wildman Read Only Funster

    Joined:
    May 30, 2008
    Messages:
    15,458
    Likes Received:
    8,598
    Location:
    Ilfracombe, Devon
    I'll give you a quid (delivered)
     
    • Like Like x 1
Loading...

Share This Page