Solar panel regulator output voltage

Discussion in 'Mech Tech' started by pkrboo, Apr 4, 2016.

  1. so i have installed my solar panels and regulator and a remote monitor so i can see what is going on.

    This weekend I noticed that the charge in the leisure battery was up as high as 15 volts. The regulator is rated to go to 15 volts but I think it may be a bit high

    what do you think?

  2. The leisure battery is knackered and has finally been connected to something that will charge it properly.

    A good battery charger may raise the voltage to around 14.4 volts before falling back to more like 13.8 to float charge the battery.

    15 volts is excessive and indicates the leisure battery has a high resistance.
    Popsy, EDE77 and snotty like this.
  3. Actually you may be on to something there, the leisure battery I have in is a secondhand unknown entity, although it has been on float with my ctek over the winter so would have thought it would be OK.

    Maybe I should just get a new leisure battery
  4. I think @mikedjames is right but just check the charge input parameter on the controller first. The panel will bang out an unregulated 16+ volts so make sure you've got a cap on it.
    The charge regulator I've got has a large heat sink to get rid of excess energy.
    Anyway, it won't be a bad thing fitting a new LB as at least you'll get true readings and good power for the accessories:thumbsup:
  5. I've seen a small solar panel on a boat give a "no-load" voltage of 19 volts, yet this drops to 12 and a bit volts when connected to a battery.
    Popsy likes this.
  6. most solar panels kick out up to 20 volts and is regulated down to 12-14 volts to charge batteries. mine is putting as much as 15 volts into the leisure battery after the regulator.

    new battery time i think.
  7. Just out of interest, what is your absorbtion voltage set at on the controller?
  8. the controller isnt that clever. it only has options to set type of battery, percentage going to each battery (dual battery charging) and the frequency (defauly of 25 hz)
  9. Ah, so for a FLA battery it must hold a set of parameters define by the manufacturer. Did the destructions for the unit indicate what these might be?
    Razzyh likes this.
  10. Looking at that the controller will bang up to 15v in.
    You were camping this weekend so presumable had a load on the system. I would expect the controller to settle down at 14.6 on the equalisation charge (setting for flooded if you've got a wet cell) with no load.
    Still, I'd be inclined to go with mikedjames' assessment which suggests high resistance. They sometimes can be bought back with a de-sulphation/re-condition such as the Ctek does. It's probably better to start with new for the new season...
  11. yes on load it was fine it was just under no load that it seemed to get a bit high, don't like the idea of cooking a battery.

    where is best to get a new battery?I got my last one at my local caravan place, i must be able to get it cheaper though
  12. What type & case size do you need? @pkrboo
  13. theBusmonkey likes this.
  14. The last one i had was a Numax 100AH LV26MF dimensions: 302 x 172 x 225
  15. Interestingly the same (bar a few amps) as my old 120 amp lucas. Built for starting as well as leisure so it may be at the end of it's life cycle.
  16. Like @67westy suggests, go for a specific leisure unit. They don't usually quote a CCA figure coz it's not relevant. That Halfords unit is a Yuasa, so a known brand.

    edit- what I mean is that anything sold as dual purpose is a compromise...but you know that @pkrboo ;)
  17. Where are you putting it? pretty sure that is the same size as the one I have and it fits in the LHS battery tray
  18. oh i defo killed it last year, ran it down to 10 volts without realising. It holds charge but not very much now!!

    I have a 85AH on in at the moment but it is second hand and old.

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