Solar landscaping lights.

Discussion in 'The Projects Forum' started by jdraughn, Apr 23, 2009.

  1. jdraughn

    Thread Starter Active Member

    Jan 30, 2009
    I have a large 12v deep cycle lead acid battery and a smallish solar panel and want to make quite a few led landscaping fixtures which will basically run all over the place. I want lights next to my driveway, around the perimeter of my yards, on my patio, ect...

    I would like to create a circuit that would at the very least shut off the lights if the voltage reaches below a certain point so as not to deplete the battery fully at night if I have so many lights that even the large lead acid battery couldin't keep up with the lights overnight.

    I will add more solar panels as nessesary to keep up with the demands of the lights, especially in the winter when I would have to have quite a few more panels because of the lower amount of solar radiation.

    I think if the battery was fully charged it could probably run the lights for days non stop depending on how many and their current draw, so having a battery like this will act as a great buffer for those cloudy days.

    Does anyone have any thoughts on this? Also, does anyone happen to know of a circuit that will do this as is?
  2. Bernard


    Aug 7, 2008
    Smallish needs to be expanded a bit, peak output V , short ckt. current. Best to limit number of LED's to to power out. of solar panel.
  3. HarveyH42

    Active Member

    Jul 22, 2007
    For around $30, you can get a charge controller, prevents overcharging, and low-battery protection. Pretty good deal, since batteries can be expensive, and worth protecting.

    I've looked into building my own, but the schematics were a little more involved than I wanted, needs some initial adjustments, and didn't seem to compensate for temperature. Not to mention the cost factor...
  4. thingmaker3

    Retired Moderator

    May 16, 2005
    A charge controller is not really needed if the PV array puts out current less than 3% of the battery's ampere-hour rating. If the PV array puts out 3% or more, then a charge controller should indeed be used.

    One may use a voltage divider and zener, a low-power comparator, and a regulator with a shut-down pin. The regulator will have to be rated for at least as much current as the load will draw.