Instructables
We recently purchased a 45 watt solar panel kit from Harbor Freight.  This kit ranges in price from $259 down to $159, depending on week and the special being offered.  We got it at the lower price.  This kit contains three 15 watt solar panels, a stand for mounting the three panels, a regulator box, and two 12 volt DC lights.  The the three panels each have 11 foot power cables that you attach to the box in parallel.  The box has a place to attach a storage battery, a cigar lighter port where you can attach an inverter, and outputs for 3, 6, 9, and 12 volts DC,  There is also a USB port with 5 volts. You get a lot for the $159.  Note, a recent check at the Harbor Freight store had on  display a much simpler regulator box. 

The downside of this unit is that if you try to use the rack that they give you for mounting, it will have to sit on the ground in a place that would be temporary.  The wind could easily knock over the panels.  There are no instructions in the package to mount the panels permanently and calling the support number got me nowhere.  After considerable thought and experimentation, I have come up with a solution that works.  The purpose of this instructable is show how I did it.

The goal was to mount the solar panels to the roof of a shed out in a country garden which does not have electrical power.  The system would generally be used to charge battery-operated tools but other AC tools could probably be used via an inverter.
 
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cege1 month ago

Good thinking!!! Thanks

MacOSJoey2 years ago
Very nice instructable! Not to criticize your work, but I've seen alternate ways of mounting this type of panel (and personally I have tried it) and it works very well. Instead of working with the bottom, many people drill a hole into the side of the panel BELOW the shallow pane of glass. A great link that explains this very well is at http://www.2manytoyz.com/hffeet.html .

Also: a little advice with your charge controller. I've seen many of these controller fail and fry batteries. Your best bet is to buy something like a Xantrex C12 or C35. Not only is it more reliable, but it offers three-stage charging and PWM charging.

Again, I'm not trying to criticize your work! Great job on such a steep slope!
rhackenb (author)  MacOSJoey2 years ago
I like the solution in the link you gave better than my solution. Thanks for the suggestion! I'm about to mount three more panels on my chicken coop was going to use metric screws to attach metal plates to the slotted brackets that slide back and forth in the side channels. I wasn't too happy with going that way but I didn't want to use the approach posted in my original instructable. Using the self-tapping #6 screws to attach right angle brackets to the side groove is much simpler.

As for the charge controller, I hadn't wanted to spring for anything more expensive at this point. I am worried, though, about the quality of the controller that came with the Harbor Freight kit. Right now this is just an experimental system and don't want to spend too much money on it. What I would ultimately like to do is put in a serious solar panel system and sell electricity back to Duke Energy, something that they won't permit right now in Indiana.

Thanks for the suggestions.
fegundez14 years ago
I recently got the battery charging solar panel from that same store and it puts out 22 volts also, That regulator was a lot nicer than the one they are selling now, but for the price it still seems to be the best deal around.
jimc45674 years ago
Good instructable. Thanks.