EHU on flat leisure batteries

Discussion in 'Tech/Mech General' started by Road Runner, Jun 14, 2009.

  1. Road Runner

    Road Runner Read Only Funster

    Joined:
    Jul 26, 2007
    Messages:
    14,196
    Likes Received:
    1,459
    Location:
    Europe
    My RV is now on a lovely storage pitch but with no electric and the leisure batteries run flat.

    Now I am allowed to move it up onto a service pitch the night before a trip but now if the batteries are really flat wont charge on hook up.

    Now once I drive it and get some charge this way instantly means the batteries will then take charge from hook up.

    Why is this and is there a solution? may a small solar panel? (as I am skint at the mo:Blush:)
     
  2. Munchie

    Munchie Funster Life Member

    Joined:
    Jul 28, 2007
    Messages:
    8,539
    Likes Received:
    11,672
    Location:
    Champagnac-La-Riviere
    Think the first question is why do your liesure batteries run flat John? Ours stands for three weeks at a time and there are still fully charged. :BigGrin:
     
  3. Road Runner

    Road Runner Read Only Funster

    Joined:
    Jul 26, 2007
    Messages:
    14,196
    Likes Received:
    1,459
    Location:
    Europe


    Good point as batteries under a year old and there is an isolator i never forget to use. Wished i remember other things so religiously:Blush:
     
  4. Munchie

    Munchie Funster Life Member

    Joined:
    Jul 28, 2007
    Messages:
    8,539
    Likes Received:
    11,672
    Location:
    Champagnac-La-Riviere
    Summat is draining them John. Might be your first port of call? :thumb:
     
  5. Losos

    Losos Read Only Funster

    Joined:
    Feb 17, 2009
    Messages:
    550
    Likes Received:
    0
    Location:
    Suffolk & Czechland
    John, somewhere on this great forum in cyberspace someone posted a long article about batteries and one of the things that really came home to me is that they run down even if there is no load, I think it's got something to do with the plates sulphating (Or something happening to the plates so the normal voltage gradually declines over time)

    The bottom line is that batteries need a trickle charge to keep them in good nick, isolating the load isn't enough.

    So, yes a small solar panel will probably help, Maplins are doing some small ones quite cheap (Sorry can't remember the price) they even have one which they say you can stick on the windscreen (with suction caps) and they claim this produces enough to keep the battery in good condition.

    Of course you also need to check the electrolyte levels regularly too.
     
  6. Wildman

    Wildman Read Only Funster

    Joined:
    May 30, 2008
    Messages:
    15,458
    Likes Received:
    8,598
    Location:
    Ilfracombe, Devon
    batteries that run flat will become dead batteries, I thought you had a suitcase solar panel that you were happy to leave connected, what happened to that, did it get nicked?
     
  7. Road Runner

    Road Runner Read Only Funster

    Joined:
    Jul 26, 2007
    Messages:
    14,196
    Likes Received:
    1,459
    Location:
    Europe

    Nope never had one but did post about them when they were cheap at Maplins.

    Would the cope with 24/7 constant use in the open as my storage pitch is secluded so have to be on the roof.
     
  8. American Dream

    American Dream Read Only Funster

    Joined:
    Aug 20, 2007
    Messages:
    6,489
    Likes Received:
    154
    Location:
    Lincoln
    A small solar panel is an ideal solution John.

    It'll keep the batteries topped up.

    All batteries have some internal resistance (even new ones) as no battery is 100% efficient (What you put in is what you get out).I wish they were, and they self discharge over time, even when isolated.

    What you don't want is for them to discharge completely, because that's when the real damage starts to occur.

    Like anything...You get what you pay for.

    Solar Car Battery Charger 30cm width x 10cm height from Natural Collection at SHOP.COM

    or

    Solar-Powered 12V 4.8W Battery Charger > Maplin

    [​IMG]

    Hope you and your Dad and Bruno are keeping well.
     
    Last edited: Jun 14, 2009
  9. Road Runner

    Road Runner Read Only Funster

    Joined:
    Jul 26, 2007
    Messages:
    14,196
    Likes Received:
    1,459
    Location:
    Europe
    Could that be left externally?

    I park my bus nose into an wooded area.

    If i could leave it outside on my bike at the back on the easylifter??


    ************************************************

    Dads not so good, worried and not sleeping at night so leaving me worn out sadly.
     
    Last edited: Jun 14, 2009
  10. American Dream

    American Dream Read Only Funster

    Joined:
    Aug 20, 2007
    Messages:
    6,489
    Likes Received:
    154
    Location:
    Lincoln
    Looked further into this John and here's some answers attached to it.

    Q- Is this unit water proof and ok for outside installation. - Keith Smith
    Answer- No sorry this product does not support that.
    Q- Is it normal for this item to put out 22v as mine does? My battery is 50amp do i need a regulator? Regards Dan - Dan Downey
    Answer- Yes it is normal but a 4.8w panel will not charge a 50amp battery you will need a 60 AMP solar panel.
    Q- is this unit suitable to be left outside all year is it waterproof - paul harrison
    Answer- No sorry this product does not support that.
    Q- Would this charger be suitable for a 70 A/h leisure Battery? Could it be left for weeks unattended? - David richards
    Answer- On this size battery a 10w panel is required for a maintenance charge (left on for ever) and for a full charge (regulator required) a 100w panel.


    Can they be connected in parallel to provide 10 watts?


    Otherwise there's



    [​IMG]
    18W Solar Panel Kit > Maplin

    Product Features



    • High efficiency crystalline cell for all-weather charging
    • Perfect for 12V appliances such as TVs or for maintaining a 12V caravan battery over a weekly period
    • Water-resistant, robust construction for outdoor use
    • 20 year cell warranty and 10 year module warranty



    Although out of stock at the moment.


    Sorry to hear your Father's not too good John.:Sad:


    Mine's not too good either.Managed to get down to see him the other week.
     
    Last edited: Jun 14, 2009
  11. Wildman

    Wildman Read Only Funster

    Joined:
    May 30, 2008
    Messages:
    15,458
    Likes Received:
    8,598
    Location:
    Ilfracombe, Devon
    I have a pair of those 4.8, one keeps the pair of engine batteries topped up and the other is in a bank with 3 larger panels keeping the leisure topped up, works for me.
     
  12. Road Runner

    Road Runner Read Only Funster

    Joined:
    Jul 26, 2007
    Messages:
    14,196
    Likes Received:
    1,459
    Location:
    Europe
  13. superk

    superk Read Only Funster

    Joined:
    Aug 22, 2007
    Messages:
    503
    Likes Received:
    57
    Location:
    Devon
  14. American Dream

    American Dream Read Only Funster

    Joined:
    Aug 20, 2007
    Messages:
    6,489
    Likes Received:
    154
    Location:
    Lincoln
    Seems ok John.

    You didn't say how many/and the Amp/hr capacity of the Leisure batteries.
     
  15. Geo

    Geo Trader - Funster

    Joined:
    Jul 29, 2007
    Messages:
    9,546
    Likes Received:
    5,596
    Location:
    Mansfield,Notts
    The batteries are going far to flat for the inbuilt charger to help them
    recover

    Your alternator when running is banging in a huge amount of amps to kick start batteries, they WILL then charge from onboard charger becuse they are now no longer flat flat:RollEyes:
    Result you will almost certaily damage your batterie if not allready and are in danger of over working your Alternator:Eeek:
    At the price of a new alternator and batteries
    a solar solution is now looking like a bargain fix:thumb:
    Do it soon!!!!
    Geo
     
  16. hilldweller

    hilldweller Funster Life Member

    Joined:
    Dec 5, 2008
    Messages:
    26,475
    Likes Received:
    25,169
    Location:
    Macclesfield
    Sounds like a poorly designed charger that you have. I'm guessing that it trips out because of the high current needed. A decent charger, like the engine alternator, just current limits and keeps charging.

    So a standard mains charger from Halfords or the like may charge it.

    Does the battery charge and hold a decent charge now ?
     
  17. Tony Lee

    Tony Lee Read Only Funster

    Joined:
    Sep 28, 2008
    Messages:
    274
    Likes Received:
    1
    It is true that most cheap taper chargers will trip out on overcurrent when hooked to a dead flat battery, but they usually have an auto-resetting thermal overload that just cycles on and off until the battery current reduces to below the trip value.

    Some quite sophisticated three-stage chargers also will not charge a dead flat battery. They either have built in protection to prevent it continuing to pump current into a seriously shorted (as a dead flat battery appears to be) battery, or they need a certain voltage to be reached (on the way down) trigger the charge cycle in the first place. Hooking up an elcheapo taper charger for a few minutes - or running the engine - will provide enough voltage to allow the charger to operate properly.
     
Loading...

Share This Page