Chicken Coop Lighting

[cmhyland]

Woodstock-20141009-00175.jpg

Hi All,
I'm a newbie to this so I have a few questions. I have a small chicken coop that I want to have a light in that will run from 5am to 8am and from 4pm to 8 pm.

I have installed a battery with inverter and a timer… I purchased a small solar panel as a charger but it was way too small at 6w. I added a second panel at 18w for a total of 24. my light is an LED at 8w. The battery I'm using is one I had… 750 CCA car battery….

I have determined the inverter is using too much power just in standby mode…. I have ordered a charge controller and a 12v timer switch to do everything in 12v. I also ordered a new 6w 12v led bulb to fit the E27 fixture.

It seems such a small demand to run a 6w or 8w build for 7 hours a day…

I suspect I need a deep cycle battery for this..

Anyone have any thoughts?

Regards,
Chris

[Wy_White_Wolf]

What's your location? Most likely the panel is still way to small. You're running the light for 7 hours a day but may only have 1 to 2 hours of insolation (sun hours) available. Daylight hours is not the same as insolation.

Something you should look at instead of willey nilley buying crap ins a light controller. Morningstars SL series would most likely work. it can be set to turn the light on at dusk and stay on for X number hours and do the same at before dawn and off at dawn. It would cut down on the wasted load of the timer.

http://www.morningstarcorp.com/products/sunlight/

WWW

[cmhyland]

I'm in Connecticut

I'm located in CT, and at this time of year I'd say we have 5 to 6 hours of strong sunlight on the days we have sun… We are a little over a month away from the shortest day of the year… The charge controller I just purchased has some of the same functions as the one one in your link. I also purchased a 12 timer switch because it can handle more than one event a day. it's draw is 6ma.

The map for insolation sunlight says we get and average of 3.84 hour this time of year.

Regards,
Chris

[Wy_White_Wolf]

Well I just ran through a bunch of locations for CT and none of them came close to 3.8 for November. You need to plan for worst case with off grid systems which puts you in about 1 to 1.5 hour average range for December and January.

http://www.gaisma.com/en/dir/us-ct-country.html

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[cmhyland]

Insolation Hours

WWW,
The site I used had Boston as the closet location. So if I only have 1 to 2 hours in the winter I guess I need a much much bigger panel.

[cmhyland]

Calcs

WWW,

The charge controller and the 12V timer switch would draw less than 30MA. so I figure I have 17 hours of them drawing 30MA. I'll have 7 hours of 700MA. So these 7 hours add up to 4.9 amps and the idle draw of the other gear is 50MA for the day.

so if we call this 5 amps X 12V equals 60 watts for the day. If I have not much more that 1 hours of insolation sunlight it would seem I need 60 watts of panel or more.

Is this correct?

Thanks for your help,
Chris

[Wy_White_Wolf]

WWW,
The site I used had Boston as the closet location. So if I only have 1 to 2 hours in the winter I guess I need a much much bigger panel.

Yes, Most likely in the 60 to 80 watt range depending on the actual winter low. With a 6w load for 7 hours means you use 42wh a day. But because of system losses you'll need to generate more than that. About twice that or 84wh with a PWM controller. So divide that by your winter low for insolation to figure panel size.

Battery will need to be sized to the panel. Sizing it to the load would create an overload with the higher charge current. Ideal would be about 2/3ah per watt of panel.

WWW

[Wy_White_Wolf]

WWW,

The charge controller and the 12V timer switch would draw less than 30MA. so I figure I have 17 hours of them drawing 30MA. I'll have 7 hours of 700MA. So these 7 hours add up to 4.9 AH (AmpHours) and the idle draw of the other gear is 50MA for the day.

so if we call this 5 AH (AmpHours) X 12V equals 60 WH (WattHours) for the day. If I have not much more that 1 hours of insolation sunlight it would seem I need 60 watts of panel or more.

Is this correct?

Thanks for your help,
Chris

I corrected a couple of you terms above.

You need to figure in system losses with using a PWM controller. You will need to generate about twice you load or 120wh.

You also need to size the battery to the panel instead of the normal way of sizing to the load. Use about 2/3ah per panel watt. Much smaller your charge rate is too high and will damage the battery. Much bigger and the rate is too low to properly charge the battery.

WWW

[inetdog]

Although if your CC lets you set a current limit for Bulk independent of the panel wattage, you can install more panel to allow better current in early and late hours.