Connect with us

Solar lights to DC

Discussion in 'LEDs and Optoelectronics' started by chur_bro, Dec 12, 2015.

Scroll to continue with content
  1. chur_bro


    Dec 12, 2015
    Hi all,

    I'm after a little help:
    I have 3 sets of solar lights, each set have 6 lights that connect together with plugs/sockets and have a seperate solar panel that plugs in that charges 3x 1.2V 600mAh batteries. On 2 of the sets the solar panel modules have ended up with moisture inside and the components have rusted making them useless.

    I noticed that I can add two extra lights to the working chain without affecting the performance but anymore and the batteries drain rather quickly.

    What I would like to do is connect all 18 lights together and run them off a low voltage transformer but I'm just not sure what I need.
    Do I use a 3.6V (3x 1.2V) transformer or do I need to increase the voltage per set?
    How do I calculate how many amps I need?

  2. Martaine2005


    May 12, 2015
    Hi chur_bro,
    That should be a fairly simple conversion.
    Are the batteries in series? so you get 3.6v.?
    I doubt they are parallel to get 1.2v and 1.8A..
    I would also imagine the 600mAh is for longer run times rather than required amperage..

    First you need to find out how they all connect together. If they connect in a series configuration, then you will need to calculate that in your power supply. 3x3.6v .
    600mA will probably be plenty for all of them..LED dependent...

    If they are parallel connected, the voltage will be the same but the amperage will be x3..

    chur_bro likes this.
  3. duke37


    Jan 9, 2011
    You should not use just a transformer, that will give you AC which is not be desired.
    You should use a power supply which gives DC regulated at the battery voltage., Make sure the polarity is correct.
    chur_bro and Martaine2005 like this.
  4. Martaine2005


    May 12, 2015
    Good point Trevor,
    I assumed when the OP said low voltage, he meant a DC brick or "wall wart" kind..

  5. chur_bro


    Dec 12, 2015
    Sorry for the late reply, things are crazy busy leading up to Christmas.

    Hi Trevor, yes I did mean a power supply 240V to ?V DC type thing depending on what is required. Sometimes the term transformer (incorrectly) is used here.

    Martin, So just to double check, I am just looking to see if the batteries are connected in series or parallel? Or am I also looking at how the lights are connected? I can check and get back to you (and post a picture if I can't work it out).

    Thanks for your responses guys, I really appreciate it.

  6. AnalogKid


    Jun 10, 2015
    All information is useful. Yes, the connectivity of both the batteries and the LEDs are needed to reverse engineer a power system. part of the problem is that solar panels are inherently self-limiting - as you draw more and more current, the output voltage goes down. A small AC/DC power supply might behave that way, or you might have to add a small circuit.

    But if we get a good enough idea of how your stuff is connected, whatever it takes to make the new system safe for the batteries becomes more clear. Another piece of the puzzle - battery chemistry. Are yours NiCad, NMH, or lithium?

  7. Martaine2005


    May 12, 2015
    I was under the impression the batteries were being discarded?
    And supplied by a AC/DC power supply only?

    Maybe I misread.

    davenn likes this.
  8. davenn

    davenn Moderator

    Sep 5, 2009
    yes agreed ... that's the way I see it too
    The battery talk is just about determining how they are wired so we can determine what voltage plug pack is needed

    Martaine2005 likes this.
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day