Newbie outdoor light project.

[yyzdnl]

I would like to know if I am on track with this little project.

I found some 1 watt 12 volt waterproof lights I would like to use for deck & garden.

Here is what I have planed so far.

Load:
4 lights at 10 hours per day for 40 Watt hours.

Charge controller:
10A Solar Lighting Controller (EPRC10-EC) dusk to dawn light control with PWM charge mode.

Battery:
12v 22Ah Electric Scooter Battery (UB12220)

Panel:
Solar Panel 85 Watt 12 Volt Multicrystalline Silicon PV

Wire:
22 gauge speaker wire, not sure about this.

Hopefully if this works well I could add 4 lights with a second battery. Any thoughts if this will work?

[Sunking]

All OK except the wire, use 12 AWG to control voltage drop and use an insulation rated for direct burial. Use the wire for 12 volt landscape lights available at any box store that sells landscape lighting like Lowes or Home Depot. 22 AWG is out of the question.

[cyberfast]

1 watt 12 volt lights

yes he is right about the wires. i'm running 3 1 watt lights to light up my water falls and learned fast about using speaker wire. burnt the wire in a week. i used landscaping wire. far as the battery i have a much bigger one and never dimmed the lights even during winter.

[yyzdnl]

Thanks guys, I hadn't put much thought into the wiring most of my time has been figuring out the rest of the project.

[Sunking]

Wiring is just as important as any other piece of the puzzle. Three things can happen with improper wiring and two of the three are bad, one real bad.

1. Undersized is the worse. The problems encountered can be as much as 20 to 50% power loss being burned up as heat from current on the wires undersized and too long for the intended current. Some system rendered inoperable because there is so much power loss the voltage sags so much equipment fails to operate. Worse of all is fire from too much current on the wires.

2. Oversize or over kill works great life is good, but you are broke from spending all that money on large copper wire. It can also be a sign you are operating at too low of a voltage say 12 volts. At lower voltages requires more current to achieve a specific power level. More current means larger wires to control power losses and voltage drop. Th eidea voltage drop on the system is no more than 2%.

Example lets say you have a 100 watt device and it can operate at either 12, 24, or 48 volts DC. The one-way distance from the battery is 100 feet or 200 cable feet. With 12 volts requires a minimum 8.4 amps to obtain 100 watts. The minimum safe wire you are allowed to use at that amperage is 14 AWG as it is safe up to 15 amps. However at 100 feet distance with 8.4 amps you would only see 5 volts at your load device and it would not even operate. In order for it to operate with only 11 volts or 1 volt drop would require 2 AWG wire. So you went from 14 AWG wire that cost 15-cents/foot to 2AWG that cost $3/ft or put another way 200 feet of 14 AWG cost $30 to $600 for 2 AWG. That should not be a problem for you right? Jump up to 48 volts and it only requires about 2 amps and you can use the cheap 14 AWG with only a 4% loss in power and voltage. Up size to 10 AWG and you are under 2% loss.

3. Get the wire size and voltage right and everyone is happy.

[yyzdnl]

wow, sunking you are a wealth of information. I wasn't to worried about the wires because this is a pretty small project. I figured I would run 12 guage from panel to battery a short distance maybe 6ft, then play with the lights and wiring when they got here.

Here is a link to the lights I am not even sure where I am going to put them on my deck depends on how focused they are.

http://www.dealextreme.com/p/waterproof-water-tight-high-powered-1w-led-module-12v-white-11263

A reviewer states this;
"Wide voltage range of operation.
@12V DC, 190mA measured.
@5V DC, 290mA measured.
No noticeable change in brightness from 5-14V DC.
Self regulating, no external resistor or driver needed."

So I wasn't too worried about the wire voltage drop since the light should still light and at 190ma I don't think I need to worry about most of your wire concerns.

For permanent installation, I had already decided on taking your original advice on the wire it is the right wire for the job. Why waste power on the wires, being direct burial rated they will last longer, the price per foot isn't all that bad.

[Sunking]

wow, sunking you are a wealth of information.

Thanks but that comes with 7 years of formal education and 30+ years of electrical engineering experience. Oh yeah also a lifetime I spent in the Navy for 3 years on a stupid submarine under pack ice.

[yyzdnl]

Project Updat & Question

Just wanted update on how this project is working out. Great, almost that is. One problem is my wifes math, it goes like this.

New deck furniture + new landscaping lighting = refinishing the deck.

Also, I am having issues with the little 1 watt lights they are too intense. They cast a great light not too bright but they light areas real nice. Problem is the light is coming from such a tiny intense point in space they will blind you if viewed head on. I tried mounting two on the top of my chimney, thinking no one looks up there. Well the deck looked great but those darn lights just draw your eye so I have banished them to under the deck rail for indirect lighting and that looks good and provides a well lit non-blinding deck. Anyone looking for security lighting might be interested in these a few well placed lights around doors and windows should guarantee any prowlers are seeing spots.

Now, that I have these running I want to get a few more to balance things out. So far my battery has been easily charged before noon on sunny days and has no problem getting charged on cloudy days.

I have some questions about roof mounting. I am not about to drill holes in the roof myself and I have to get hail damage repaired. Is mounting something any roofer could do or are there legal issues that require licensed installers? Right now I have a temporary mount off the deck. My panel came with L brackets for roof flush mount and I am OK with that but would I be better to put up some rails that I could attach more panels to in the future since I will be paying to have someone install? If so what type of rails are used?

Thanks again for your input,
Daniel