leisure batteries on permanent charge

Discussion in 'Motorhome Chat' started by lebesset, Apr 30, 2010.

  1. lebesset

    lebesset Read Only Funster

    May 31, 2009
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    haven't used the motorhome for a few weeks now , and it suddenly occurred to me that the batteries are being constantly charged by the array of solar panels

    so I put the meter on the 12v output to see what voltage they were actually showing ...answer ...13.9 volts

    question is , is it ok to constantly keep the batteries at this voltage[ well , not overnight I presume ], I am aware that the amperage isn't that great , but don't really know if the batteries being kept under charge will suffer any damage at this level

    any info on this ?
  2. Wildman

    Wildman Read Only Funster

    May 30, 2008
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    Ilfracombe, Devon
    unless your solar charge regulator is faulty the charge rate will have reduced to a milliamp float charge and is quite normal. the charge rate will rise as you put a load on it.
  3. Douglas

    Douglas Read Only Funster

    Aug 22, 2008
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    South Wales,
    There are some cheap (14 euros) non smart chargers about that use a simple relay to turn the charge on and off. They take the charge voltage up to 14.2v then turn the charge of until the voltage comes down to 12.6v.

    I have had one for about 4 years and it works great, when the MH is not in use the battery's take over a week until the voltage has dropped low enough to start the charging again.

  4. atakd

    atakd Read Only Funster

    Nov 15, 2009
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    Some info below I got when posting on solar charging on a sailing forum. I decided to stay with my basic regulator but if it fails I will probably upgrade to a PWM.

    I have a 40W panel and one of these


    regulators. When the panel charges the battery in bright sunlight the voltage rises rapidly then charging ceases for a while, then resumes.
    My question is, do all regulators deliver pulsed charging, meaning precious periods of sunlight go unused, or is a regulator available which limits charging current whilst delivering a safe, continuous charge? Or does it make no difference?

    I recently went thru this for a 30W panel. Basic advice on here was to get a PWM (pulse width modulation) regulator- much more efficient than standard regulator and not much more money- cost about £15-£20 and I paid £28.99 for a 2 battery unit.

    Better still is evidently a MPPT regulator (multi-point tracking- about 30% more efficient than PWM) but these are still pretty costly- cheapest about £50-£75 for a single battery unit on Ebay.

    If you want an LCD readout for charging rate, battery state and charge etc, then these units are normaly £100+, tho I did get an add on meter for mine for £36, which was pretty good value I feel.

    HTH ​

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