Completely flat

Discussion in 'Motorhome Chat' started by highwayman, Apr 14, 2012.

  1. highwayman

    highwayman Funster Life Member

    Jul 31, 2007
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    Kent coast
    Hi Folks
    Got a new leisure battery, and somehow turned the charger off in the van :Doh:
    We ended up with a completely flat battery that wouldn't even iluminate a light let along move the needle on the battery gauge.
    Now the thing-is it charged up ok and has held a charge all winter albeit not to the top of the gauge, but should i trust-it or not??
    I'm leaning towards not,:cry: but at less than a year old and a cost of £100 i don't want to throw it away. Dunno what to do so i thought i'd ask the experts.
    Another thing, to connect another battery and double our capacity it's positive to positive and negative to negative isn't-it??

    cheers nige
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  2. darklord

    darklord Read Only Funster

    Apr 28, 2011
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    You are correct in the pos to pos etc bit. You need to test the battery, if you connect a duff one to a good one, you;ll not really gain anything and could cause problems. Did the battery have a warranty? if so, it was probably two years........? Halfords will do a drop test on if for you, or you could do a simple test by turning stuff on and seeing how long it lasts....good luck.
  3. pappajohn

    pappajohn Funster Life Member

    Aug 26, 2007
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    YO11 2BD
    if its still holding charge it sounds like you may be Ok.

    you could do a load test with a known load to be sure using something like a 50watt car spotlight bulb and a digital voltage meter.
    a regular charger wont fully charge the battery but it will be close enough to test.

    let the battery stand 'off charge' for a couple of hours.

    connect the meter to the battery and check voltage (should be 12.6v/12.7v), then connect the bulb as well.

    check the meter regularly.

    a 50w load should bring a 110ah battery voltage down to 12v (50% charge) in around 13 hours.

    if the battery is knackered the time will be greatly reduced.

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