Leisure Battery advice

Discussion in 'The Beginner' started by Steely Daniel, Mar 29, 2015.

  1. Steely Daniel

    Steely Daniel Read Only Funster

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    Hi
    I am new to Motorhome Fun and this is my first contribution. I have just acquired a used 2010 Swift Sundance 590 which I am extremely happy with.
    However I just need a bit of advice regarding the leisure battery.
    Basically, after driving the van for a decent trip of around 100 miles if I go into the van and turn on the power after a couple of daysI get warning sounds and lights that tell me that tell me that the leisure battery only has about 10 volts in it. I would presume thus indicates a duff battery but the battery has an indicator light which is showing green.
    I suppose my question is how I know if the battery is charging and should I take any notice of the green indicator or are these unreliable?
    No doubt this question has been asked a hundred times before, so if someone could tell me where to look I would be most grateful.
     
  2. pappajohn

    pappajohn Funster Life Member

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    If its dropping to 10v after a couple of days its time for a new battery.

    It does depend on your useage though.

    Warm air heater fans will soon drain the battery if used for a while.
    standard lights will also use a fair bit.
    a modern tv may use 2 amps per hour......5hrs a day is 10 amps which could be 20% of your available power....times that by two days.....40%.....assumimg a single 110ah battery.

    You need to regulate how much battery power you use and keep it to a minimum where possible.
    turning off lights not immediately needed will extend the run time.

    But it does sound like your battery has seen better days.
     
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  3. Steely Daniel

    Steely Daniel Read Only Funster

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    Thank you for your advice. As far as I am aware, nothing is on in the van and when go back into it a couple of days after a journey and turn on the power it alerts me that I only have 10 volts almost immediately.
    What I don't get us that the battery had an indicator window which is showing green, which apparently indicates a healthy battery. Are these indicators unreliable?
     
  4. Jonkil

    Jonkil Funster

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    Charge your battery. Let the standing charge stabilise. Put an ampmeter in series and check if you have a drain with all switched off...... Could be something demanding current...... but
    As others have stated, your battery may have seen better days.

    But better you check first, as a new battery will drain too if there is a demand on it.
     
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  5. mjltigger

    mjltigger Funster

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    The indicators aren't very reliable. They Help with battery condition but not charge in my experience.
     
  6. JeanLuc

    JeanLuc Funster

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    Start by giving the battery a really good charge from 230V hook-up. A drive of 100 miles may not be sufficient to restore what you have used, particularly if you have a gel battery as these take longer to charge than wet lead-acid or AGM types.
    It is good practice to do a hook-up charge before and after a trip - also periodically whist you are touring.
     
  7. Lenny HB

    Lenny HB Funster

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    If before you did your100 mile the battery was fairly flat a 100 miles is nowhere near long enough to fully charge it. Best to hook the van up to the mains for a couple of days to the battery fully charged then see how it goes.

    Battery condition is always measured with the battery off load after letting it rest for at least half an hour.
    Sounds like you got your 10 volt reading when the battery was under load so your battery is probably OK.

    If you got two full days out of it after only a 100 mile drive to charge it, I would say you did very well.
    If you only have a single battery depending on your load I would only expect 2/3 days out of a fully charged battery.
     
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  8. Techno

    Techno Funster Life Member

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    The charge indicator light is only connected across one of the 6 cells in the battery, it will not indicate if any of the other cells have failed BUT at 10 volts it would tell me that is the case.

    EDIT plus one on what Lenny said (y)
     
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  9. pappajohn

    pappajohn Funster Life Member

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    At 10v with no useage at all after two days means that battery is no more....its dead.

    After 100 miles i wouldnt expect it to be much over 12v which is still too low.

    if constantly allowed to drop to 10v the battery is already damaged beyond repair.

    If the 10v is under load it must be quite a high load and would drag the battery even lower quite quickly.
     
  10. Steely Daniel

    Steely Daniel Read Only Funster

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    Hi
    Thanks to everyone for their helpful advice. I think that I was under the false impression that the habitation battery would basically charge up much in the same way that the a healthy car battery appears to essentially be fully charged after a fairly moderate journey in the vehicle. I presumed that the van alternator went on to charge the habitation battery once the vehicle battery was fully charged but I think that I am not right in believing this is the case.
    I think I will take the battery out and charge on a separate charger and see how the voltage reads after doing this and connecting back to the van.
     
  11. tonyidle

    tonyidle Funster

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    A healthy car battery is rarely discharged by more than a few percent. With an engine in good order it's asked for, say, 400 amps for less than 5 seconds to start the engine = less than 0.5 ampere-hours which will be replaced in a very short time by the alternator. On the other hand the leisure battery even if only discharged to 50% of capacity will ask for 50 Ah. Which will take a very long time to replenish.
     
  12. JeanLuc

    JeanLuc Funster

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    1. The alternator does charge both starter and leisure batteries. It just needs quite a long drive to recharge once you have discharged the leisure battery significantly. Tony's post above explains this.
    2. I would not bother to remove the leisure battery to charge it. Just plug in to a 230v hook-up and the on-board charger will give the leisure battery a proper charge. I don't know anything about Swift vans, but all modern motorhomes have an intelligent, multi-stage charger.
     
  13. Lenny HB

    Lenny HB Funster

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    I believe Swift only use a standard split charge relay to charge the leisure battery, with this type of arrangement they also tend to use fairly small cables which gives a volt drop which does nothing to help the charging. When you first start the engine the leisure battery will charge at about 10 - 15 amps (depends on the wiring) after ½ - 1 hour the terminal voltage across the battery will rise and the charge rate will drop to 4 or 5 amps maybe even lower, that's why even driving all day is unlikely to fully charge a flat leisure battery.
    If you need the battery to be charged more efficiently while driving you could fit a battery master or similar product which will enable leisure battery to charge at a higher rate.
     
  14. SomeoneElse

    SomeoneElse Funster

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    That may be true of continental MH but is not true for the two British vans I have had, a 2010 Elddis Autoquest and a 2013 Bailey Approach.
    Both those van had a 12V power supply unit which is not regulated but have a no load output of 13.8V. It makes a good float charger but takes longer to give a full charge. I wouldn't be surprised is Swift with the same history of Caravan manufacture as Elddis and Bailey didn't have the same. In which case an EHU charge will take a two or three days to get anywhere near a full charge and it will never take it up to absorption voltage. an external charge with a three stage charger of at least 5A would be better. The other danger of using this type of PSU to charge a leisure battery is the with a very low voltage from the battery the PSU may push a very high current towards the battery and blow the battery fuse. Elddis use a 15A and Bailey a 20A rated fuse on the battery line.

    To give any real advise to the OP a voltage reading actually at the battery is needed, but dealers know that fitting a new battery corrects 99% of these sort of faults. They then only have to investigate the odd few cases that return, usually with the statement "never seen anything like this before" :sneaky:
     
  15. Lenny HB

    Lenny HB Funster

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    Blimey that's 1980's caravan technology, one would have thought they have moved on since then.
    I thought Swift now fit Sargent unit which I thought we multi stage chargers.
     
  16. JeanLuc

    JeanLuc Funster

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    I stand corrected - I too thought Swift fitted Sargent chargers. Seems a bit archaic not to fit a decent charger.
    By the way, the item that boost charging whilst driving is a Battery-to-Battery charger, (B2B) not a Battery Master.
     
  17. SomeoneElse

    SomeoneElse Funster

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    I have no knowledge of Swift, my suspicions were based on them having a history as a British caravan manufacturer. I rarely ( ie not in the last 12 months since fitting solar panels) used EHU. My solar controller is a proper three stage charger and works well.

    The way Elddis/Bailey are wired ensures that the 12V appliances are never subject to more than 13.8V. I worried a little that the solar controller would subject them to 14.4V, which it does but they tolerate that voltage and still operate without problems.
     
  18. Lenny HB

    Lenny HB Funster

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    I was being lazy couldn't remember which one did what & couldn't be bothered to look it up.:)
     
  19. Steely Daniel

    Steely Daniel Read Only Funster

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    Thanks again to everyone for sharing their knowledge. I have definitely learned a few things about how the battery system works in a Motorhome.
    Just to update, I have taken the battery out and connected a jump starter/ charger directly to the battery on its low powered setting. Before any charge, the battery read 12v on a multimeter, and after an hour on the charger it was up to 13.8v. All this suggests that the battery could be OK and I will put it back in the van tomorrow and see how it performs with a load on it.
    My van has a recessed plastic compartment in the floor which will accommodate a second battery. So I have decided to add a second battery which seems a good upgrade, with the only downside being obviously the added weight. What has prompted me to add a second battery is the 15% discount which is available until tomorrow evening at Go Outdoors. This brought a fairly decent low profile 100ah leisure battery down from £80 to £68 which seemed pretty reasonable. Only condition is that you have one of their discount cards. I hope this may be if use if anyone else is thinking of changing their battery.
     
  20. DavidG58

    DavidG58 Funster

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    just be slightly wary of the second battery (new battery) being dragged down by the first (original) if it is still on the weak side, we have had exactly that, one good, one failed, nothing worked on 12V off charge

    generally the advice seems to be to fit 2 new batteries at the same time

    if funds allow that is what I would recommend you do, we did, although in fairness then found that one of them was fine :)
     
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