I finally got moving on assembling and mounting the panel that I picked up from Harbor Freight a while ago. Unlike the more expensive panels that are out there, these come without blocking diodes. One needs to be installed manually to compensate for this shortfall. Fortunately the local Radio Shack has the needed diodes in the rectifier drawer in the components section. The ones that I located are rated for 6A @ 50V, more than adequate for the need at hand, the price was right too at $2.99 for 4 diodes.
The wiring that comes with the panel from Harbor Freight included a cigarette lighter plug, battery clamps and bare wires, the last is the only one that I really need for this application. The first thing that needs to be done is to strip back the shrink tubing that they put on the outside of the two DC leads, this needs to be done to provide adequate room to solder the diode in-line. Since I have not explained it earlier, the diode only allows current to flow in one direction. This is important when charging batteries because when the sun goes down the panel becomes nothing more than a large resistor that will drain all the energy back out of the batteries during hours of darkness (this kinda defeats the purpose).
DISCLAIMER: Don't let your wife come home and catch you doing this on the center island in the kitchen, leave no trace
After the tubing is trimmed back to expose more of the wires, the positive lead is cut to incorporate the diode. Note: in the following picture the diode is laid out backwards, the band goes towards the part of the circuit that you want to prevent current from flowing from.
Next, solder the diode in-line on the positive lead (the diode is oriented properly this time). One piece of advice, make sure that you have a soldering iron that is big enough to do the job or else you will end up with crappy solder joints like mine in the picture
Once you have the diode in place, and everything has cooled off enough, it needs to be sealed to keep out the elements. In this case I first used a piece of shrink tubing, then wrapped the diode and wire in silicone tape (Rescue Tape / X-Treme tape).
Mounting the panel.. This was not so fun. The first comment that I have is the fact that the mounting hardware (if it can be called that) provided by Harbor Freight is crap! Rummaging through my various stores of parts, pieces, doo-dads and the like was my only saving grace in getting this thing mounted. Even though the mounting hardware sucks, the panel was still well worth the money spent. Well, that's my opinion now, it may change if the thing dies in three months..
I ended up using standard hangers for framing to make the connections to the roof, and a leftover piece from a sat dish installation for the upright bracket. Rube Goldberg would be proud..
The actual hookup to the generators battery will come soon enough, I have already tested the panel with a 12V device that requires a full amp to charge and the panel performed wonderfully in partial sunlight. The picture above shows the panel's output of 24V without direct sunlight at approx 3:45 in the afternoon (it gets pretty dark by 4:30).
Total spent so far: approx $70.00
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