Wired path lights from single solar panel

[spillenger]

I have an off-grid cabin where we get all our power from solar. The path from our parking area to the cabin is about 100 yards long and pretty dark even during the day. My wife has installed about 20 small solar lights along the path, to help guide people at night but also because they look cool. However, since the solar panels on these lights sit in the dark all day, they don't get charged unless she collects them all in the morning, puts them in the sunshine all day, and returns them to the path at night.

This is a hassle.

What I want to do is mount a solar panel in a place where it gets lots of light, connect it to a small 12v battery of some kind and then use that to power as many 12v path lights as we want -- maybe even figure out a way to hook up the juice to some of the cool solar lights we already own.

Questions:

Do they make 12v solar lights that I can use for this?
Do I need a charge controller for this application?
Any particular gauge wire I need to use to connect the lights to the battery?
Can I daisy-chain the lights?
Any ideas on how easy or possible it might be to use the funky solar lights we already have in this way?

Many thanks,
Paul

[kalefinn]

As far my knowledge you should go with charge controller for this application and the one with which you can go is Morningstar Sun Saver SS-10-12 V, 10 Amp Controller, as one of my friend is also using it in his home.

[Mike90250]

The big garden light companies (Toro, Intermatic, Malibu......) mass market whole 12vAC kits, and you can also get 12V LED replacement bulbs. Price shop getting a kit, vs creating a system from scratch.

Your existing lights most likely run on 2.5 volts, and would be painful to try to convert to 12V.

Get the lights, convert to LED bulbs, and then depending on the total wattage, we can size properly, a
PV panel, battery and charge controller.

But plan it first, run the plans here, then spend money. Do not buy a random pile of parts and then ask
why it does not work and the battery is dead

[Sunking]

The path from our parking area to the cabin is about 100 yards long and pretty dark even during the day.

Well at 100 yards you are dead in the water. The amount of copper required at 12 volts will require a copper mine. Only way to efficiently do this is with 120 VAC and multiple 12 volt transformers installed at strategic locations as 1 way distance is limited to 20-30 feet from each transformer. I would have to look at the specs for LED systems as you might get a little more distance but it really depends on how close the lights are together and the wattage of each light. But you are talking serious money.

[paulcheung]

There are 120 volt 3 watts AC LED bulb use the regular receptacle, I use them around my house and I don't even bother to turn them off during the day when I forget. they use very little energy I have about 10 of them around the house and yard.

You can get some of those bulb, If your cabin is wired 120 volt then you just get a pair of wire carry out to the passage, if not you need to get a small inverter like 75 to 150 watts, AGM battery and matching charge controller with matching panel(s).

Cheers.

[Shockah]

100 yards is quite a distance for DC voltage string.

00o0o_jwNLKpF57An_600x450.jpg

You should consider stand alone units like this.

@ 400lumens each, 4 units would put a nice glow on your path.

Also, with stand alone alone units, if you suffer component failure on one unit,
the other units still work...
unlike the entire string of units shutting down if say the controller failed or battery died.

[SunEagle]

100 yards is quite a distance for DC voltage string.

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You should consider stand alone units like this.

@ 400lumens each, 4 units would put a nice glow on your path.

Also, with stand alone alone units, if you suffer component failure on one unit,
the other units still work...
unlike the entire string of units shutting down if say the controller failed or battery died.

Those lights would work but the OP states that where the lights are placed there is very little sunlight to charge the batteries. He needs a centrally located solar panel system in the sun and then has to figure out how to power all those lights over the 100 yards.

As you and others have mentioned the wire size would have to be big at 12 volts. It might be cheaper to just use a 120vAC circuit with direct burial cable to each light. Not the cool solar equipment he was looking at but it probably would be much cheaper to install and run than a solar battery system.

Of course I just reread his first post and realized his cabin is off grid so the AC circuit may be hard to do as well.

[Johann]

Those lights would work but the OP states that where the lights are placed there is very little sunlight to charge the batteries. He needs a centrally located solar panel system in the sun and then has to figure out how to power all those lights over the 100 yards.

As you and others have mentioned the wire size would have to be big at 12 volts. It might be cheaper to just use a 120vAC circuit with direct burial cable to each light. Not the cool solar equipment he was looking at but it probably would be much cheaper to install and run than a solar battery system.

Of course I just reread his first post and realized his cabin is off grid so the AC circuit may be hard to do as well.

Yeah, his cabin is off grid, but there are still other options.
It is to bad that the OP did not mention how many light and the wattage he/we are dealing with.

Those lights could still run of an small 120 volt inverter with an timer or photo cell on it and I think it would be the cheapest and easiest way to do.

Or, have an nominal 48 volt dc system for the light and with this increased voltage your wires could be smaller. I know 48 volt light bulbs are not common. Let.s redo that 48 volt system a little bit, but it will cost bit more.
Low wattage solar panels = 48 volts nominal.
Batteries =48 volts, charge controller for 48 volts nominal and all sized for the load.
Right sized wire for 100 yards for that given amperage and a 48 volt nominal.
Now we need to make drops for each individual light. We use a 48 volt to 12 volt buck converter(more losses) etc, that is hooked up between the 48 volt dc line that comes from the battery and the light. And you are ready for your 12 volt light.
It is more expensive, but it would work.
And if the solar panels, batteries and charge controller are placed halve way into the length of the driveway, then the distance for the wire run would come down to 50 yards running in opposite directions .

[Sunking]

Well I have no idea of how many lights he/she intends to use on this 300 foot path, but based on using 1.5 watt LED's (lowest the make to my knowledge for landscape LED's) with 10 foot spacing on both sides of the path is going to be around 60 fixtures and a 90 to 100 watt load which is fairly large when you consider it is continuous and likely will be on for 10 hours or a 1 Kwh.

Only feasible way to do this is use a inverter to supply six magnetic 12 volt transformers spaced every 50 feet.