If you have a new account but are having problems posting or verifying your account, please email us on [email protected] for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact [email protected]

Solar panel question

  • 28-05-2021 10:00pm
    Registered Users Posts: 1,405 ✭✭✭

    Got a solar panel for a shed LED system, the panel is 100w and I took it out and measured the voltage, 20v normal sunny day.

    What Im worried about is, is my charge controller for my 12v batter is

    which lists 18v as the max. I know the things change once you apply a 'load' to he circuit, I measured the 20v by sticking the multimeter probes directly to the panel.
    Am I in trouble to try and use the panel with that charge controller?


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 62,624 CMod ✭✭✭✭unkel

    No, it's fine. Don't worry about it. I've used them like that without any issue. As soon as you put a load into the battery, that voltage will drop anyway. And those solar charge controllers cost about €4 directly from China, so not the end of the world if one should fail :D

    What panel did you get?

  • Registered Users Posts: 1,405 ✭✭✭jogdish

    unkel wrote: »
    No it's fine. What panel did you get?

    I got this one, The charge controller arrived this morning and says 18v max for a 12v batt. Why is it fine to use it?

  • Registered Users Posts: 439 ✭✭phester28

    not sure of your particulars but if you measured VOC at 20V (no load on the panel) then you will not have to worry about it. The controller is supposed to handle the turn off charge voltage. if you have any small 12V battery stick it on and monitor the voltage, as it charges

    These controllers are cheap (very cheap) and even the voltage part of it have a tendency to be off (by as much as 1V) so you may have to adjust the turn off voltage on the controller. And verify its voltage accuracy