Solar Panel Addition

[mikehhfx]

Hi All

Just thought I'd share this with you.

We have a 2007 Popup with just the ice box and stove. I have the 12 volt battery running the interior lights.

We like to dry camp, so i wanted to be able to run my 12 volt cooler and a few goodies from the battery, but am worried about it having enough reserve power.

This weekend I bought a 15 watt solor panel (99.00)a charge controller (29.95),
hooked it to the battery, and put the panel on the roof. and hooked the cooler to the battery, the cooler ran for 6 hours, and it did not deplete the battery charge at all, in fact it ran the cooler and charged the battery.

So I guess it's going to work, now I am going to put 2 - 12 volt accessory outlets  in the cupboard panels, so that I can just plug an accessory in, and wire up some connectors so I can just plug and unplug the charge controller and solar panel.

Anyone have any other thoughts.

[wernstriumph]

Where did you get the solar panel? I was thinking of doing the same thing but the inexpensive  panels I found were only 1.5 to 5 watts( not enough to bring the battery back up after a night of running the furnace.) $99 seems like a decent price.

[mikehhfx]

Where did you get the solar panel? I was thinking of doing the same thing but the inexpensive  panels I found were only 1.5 to 5 watts( not enough to bring the battery back up after a night of running the furnace.) $99 seems like a decent price.

I live in Canada, Canadian Tire sells them.. they are on sale this week for 99.00 marked down from 169.00.

//www.canadiantire.ca


mike

[wernstriumph]

Thanks for the link!:)

[austinado16]

Wow!  Nice score!
Do you know if they'll ship to the US if I buy from them online?

[chasd60]

This weekend I bought a 15 watt solor panel (99.00)a charge controller (29.95),
hooked it to the battery, and put the panel on the roof. and hooked the cooler to the battery, the cooler ran for 6 hours, and it did not deplete the battery charge at all, in fact it ran the cooler and charged the battery.
 
 
Anyone have any other thoughts.

Yep,
A 15 W solar panel will output 1A after the charge controller if your lucky. I don't understand how you could have powered the cooler let alone charged the battery. What brand cooler do you have? The Coleman PowerChill has a 4A supply although it probably doesn't max out at 4A.
 
45W for $199 here
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90599
And they have a charge controller for $30 too

[austinado16]

Wow! That's a nice setup, and 3 times the power for $100 extra!  Geez.....any other better offers out there?

[wavemaker]

i got mine about a yr ago.. and i say it works ok...
 
now i just want a 200amp setup so i can run a couple of 120volt
applications...

[wavery]

i got mine about a yr ago.. and i say it works ok...
 
now i just want a 200amp setup so i can run a couple of 120volt
applications...

I think you mean 200W set-up but yes, IMHO, that would be a nice set-up.

A 200W array would give you about 80A of charge on a good day in full sun. That's about the same as running a 12A charger off of a generator for 6 1/2 hours or a 25A charger for about 3 hours.

I think that a 100W array would be a good starter set-up with the ability to add another 100W if you feel the need. A decent 100W array would cost you about $600. That's a lot lees than a decent generator but it is a lot less reliable too. There are pros & cans to both.

mikehhfx that 15W array is what one might use to stabilize a battery while not in use. It certainly is not adequate for charging a battery and certainly does not require a controller unless you are going to leave it on the camper in storage.

[chasd60]

http://www.partsonsale.com/campers2.html

[wavery]

http://www.partsonsale.com/campers2.html

Thanks for the link  :book: . We are considering solar for our home in Fallbrook California. There is a lot of helpful info on that site.

They claim to be able to get us into a 7000W array for $24,335.69. If they can do that, they've got a sale. I'll keep you posted.

[mikehhfx]

Yep,
A 15 W solar panel will output 1A after the charge controller if your lucky. I don't understand how you could have powered the cooler let alone charged the battery. What brand cooler do you have? The Coleman PowerChill has a 4A supply although it probably doesn't max out at 4A.
 
45W for $199 here
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90599
And they have a charge controller for $30 too

The Cooler i have is a Koolatron Thermoelectric cooler using the latest Peltier Devices, if that helps,  the Av adapter says it outputs 13v at 5A. The solar panel states it puts out , as you said 15w at 1A. I have not answer for how it worked, I'm no electrical engineer, all I know is that I checked the voltage on the battery with my volt meter before a hooked it all up and check it regularly, and the charge went up and the cooler kept running.

Mike H

[Nemesis56]

The Cooler i have is a Koolatron Thermoelectric cooler using the latest Peltier Devices, if that helps,  the Av adapter says it outputs 13v at 5A. The solar panel states it puts out , as you said 15w at 1A. I have not answer for how it worked, I'm no electrical engineer, all I know is that I checked the voltage on the battery with my volt meter before a hooked it all up and check it regularly, and the charge went up and the cooler kept running.

Mike H

I'm totally confused...  and  I am an electrician.. not saying it dosen't work, but your cooler should be drawing 65 watts ( 13v X 5a= 65 watts).  15w @1a is illogical. Since watts is volts X amps, you  would have 15volts  at 1 amp output on your panel.  The web site says 15watts  at 12 volts which should =1.25 amp(watts/amps)... if you divide volts into watts it drops down to.80 amp....either way no where near enough to run you cooler and charge a  battery...What probally happened is you were reading the voltage drop with the panel operating and getting a 12volt output.  Anyway...I'm glad it works for you.

[chasd60]

I'm totally confused... and I am an electrician.. not saying it dosen't work, but your cooler should be drawing 65 watts ( 13v X 5a= 65 watts). 15w @1a is illogical. Since watts is volts X amps, you would have 15volts at 1 amp output on your panel. The web site says 15watts at 12 volts which should =1.25 amp(watts/amps)... if you divide volts into watts it drops down to.80 amp....either way no where near enough to run you cooler and charge a battery...What probally happened is you were reading the voltage drop with the panel operating and getting a 12volt output. Anyway...I'm glad it works for you.

When it comes to solar panels you have to employ funny math.
I have 80W panels that are rated as 12V nominal. My 80W/12V should equal 6.7A but............................
The 80W comes from 17.3V output which is 80W/17.3=~4.63A
17.3V going thru a typical pwm charge controller will drop the voltage to 13.5V or so and that really equates to 13.5X4.63A which only equals 62.5W. Being DC, you can't step down the voltage and step up the current like you can with AC.
 
Panel voltage output is temperature dependent and derated with heat. Make one that outputs 17.3V at 75F and you still have usable ouput when the temperature of the silicon is 130F or hotter in the direct sun.
 
Whe you use a 15W panel with a big load or a large battery deficit, you can bypass the charge controller and maximize the total power. Just keep track of the battery voltage during this process.
 
I think "wavery" and I have had this discussion in the past. Add a switch to bypass the charge controller. When the battery is down 30AH and you are only producing 1AH, you will be pretty safe to let it run all day long without a charge controller. The internal battery resistance with the charge deficit won't allow the battery voltage to get too high.
 
I do know that my 160W total with a MPPT charge controller and two 110Ah batteries wired in parallel allow me to pretty much use power at will. I am the only one in my camper that even worries about conservation. It seems like we use more power leaving things on and unused than we do while using them. That is why I got rid of the 2.8A lights and installed .4-.5A fluorescent lights.

[chasd60]

The Cooler i have is a Koolatron Thermoelectric cooler using the latest Peltier Devices, if that helps, the Av adapter says it outputs 13v at 5A. The solar panel states it puts out , as you said 15w at 1A. I have not answer for how it worked, I'm no electrical engineer, all I know is that I checked the voltage on the battery with my volt meter before a hooked it all up and check it regularly, and the charge went up and the cooler kept running.
 
Mike H

It is possible to have a surface voltage above the actual battery voltage even with a reduction in Amp/hours. Remove the charge and allow the load to continue for 3 minutes or so, then recheck the voltage. This removes the surface charge and gives you a more accurate reading of battery voltage.