Ran some tests on the modified 12 volt Coleman Cooler in the first weekend of July.
It just happened to be one of the hottest weekends in our area. Afternoon day temps hovered around 28*C or 81*F and it was a dry heat. Living on the West Coast, I’m just not use to that type of heat. I’m so glad the lake is nearby and I can go for a swim to cool the core off.
To power the fans and the cooling Peltier module, I pulled out the old 60 Watt Frankenstein solar panel I made a few years ago. It was easy to set up, but it may not produce another amperage for the Peltier module. But this was for testing only. Hooked it up with some basic alligator clamps and switched on the power.
For testing the temperature inside the cooler, I used the refrigerator/Freeze thermometer from the Frost King Ice Box.
Starting temperature was at 80° F
At 12:17 (high sun) Checked the cooler. It read to 70°F. Not really impressive. So I repositioned the solar panel to get maximum sun.
3:30 pm – The thermometer read 80*F. What, back to the starting point? Could it be the lower solar output. The fans were turning, but not enough juice for the Peltier module.
5:00 pm- No change, 80°F. Almost no sun in my location (It was hiding behind the trees)
What I did next, was hook the modded Coleman Cooler right up to four, 6-volt deep cycle batteries. The batteries would produce the amperage required for the Peltier.
7:00 pm- Slightly cooler by 2 degrees, but that could be due to the ambient temperature.
The end result: Not a total fail. Some upgrades will be necessary to get it running properly. I would conclude the bottleneck is the size of the wire/fuse on the power plug. The wire and fuse set up was taken from a DC power vacuum for a car. Judging by the size of the motor, it only needs an amp or two to make it run. A YouTube reader suggested a power cord from a heated seat mat or DC heater fan. They are rated at 8 amps, which will provide the necessary amount of power to run the Peltier cooling module. I’ll keep my eyes open for one at my local recycle center and then make another video.
Did some research on the web and these panels are said to produce power in any sunlight light or cloudy days. Thought that would make an ideal trickle charger for smaller batteries that start the gas generator or future 12 volt LED lights for the cabin
When it finally arrived in the mail, I did some tests and it pushed out 24 volts at .25 amps (open, no load). The numbers are low, but the panel was lying almost flat on the ground.
Since it was small and square, thought it would be ideal to mount it to the Satellite TV Dish. There was a just enough space under 100-watt panel.
I got to work creating some “Z” clamps from a left over piece of angle metal. I measured how thick the solar panel was and marked it as the bend point of the metal. Unlike the first time make these Z clamps, I measured out spaces for the widths of the clamps. Using a permanent marker, I was able to show where to bend and cut the holes for the bolts.
Note: Might not seem like a big deal to measure, but most of the time, I’m under some imaginary deadline and I thinking about the next step even before I’m finished the step I’m working on. It’s like flying-on-the-seat-of-your-pants working. Sometimes great ideas come out of it, but, the result is sloppy workmanship.
Using a cordless drill with a 1/8th bit, made a hole in each Z-clamp so it cloud be fit to the IKEA slide rail. Grabbed the 4 amp trusty angle grinder, plugged it into the 1500 watt inverter and fired it up. With the thin cutting blade, it sliced through the metal angle iron no problem. I took my time rounding the edges of the metal, so it didn’t have nasty burrs, to slice my figures.
Once the four Z-clamps were bent and ready, I went up on the roof for sizing the panel the rails. That is when I noticed my oversight. The space left over on the satellite TV dish mount was not enough. About 3-1/2″ too short.. odd, didn’t look like that from the ground. Anyway, it was a minor set back, but I had an idea on how to add an extension arm to the bottom of the IKEA rails. Went and rummaged through my pile of old solar panel mounts from a few years back.
Found two,1″ x 9″ pieces of stainless steel metal with pre-drilled holes. The first thought was to put the two Z-Clamps on the ends and bolt it onto the rail. When I went up on to the roof to do some rough measuring, I noticed the 9″ strips slid nicely inside the rails, sweet!
That worked so much better than the previous idea. To help secure the 9″ strip in the rail, I used a small 1″ carriage bolt with a lock washer and a washer. The lock washer added just enough tension to keep the bolt from sliding out. I went back to the solar panel and measured its width, 13-3/4″. Then I slid the extension arm up into the rail and adjusted it so the panel would sit neatly. Slid in the solar panel side ways and tightened it up. Nice!
It worked out better than I thought, the panel was very secure, but not too much weight for the mount.
One of the problems with a DIY (do-it-yourself) solar panel was removing the solar cells from the outside glass. Have to be really careful to not crack are scuff the wafer thin cells. Solar cells have a blue and gray surface. The blue surface faces the sun. During assembly, tiny dab of silicone should be added to the blue side and then attached to the glass panel. It ensures the strings of solar cells don’t shift around while the encapsulate applied (Slygard 184 or EVA). If the glass gets cracked, bit’s of glass should slide off to the fragile cells. So the choices are: carefully remove the cells from the glass and use a new sun facing glass, fill the cracks with a waterproof expanding sealant, or add another layer of glass. I went with the latter and used a single pane window.
Single pane windows work great for DIY solar panels. They already have the frame and easy to find. Normally find them up for free. I then use aluminium “C” channel on the ends to help hold the new window to the old. A banding of some sort also helps. Careful from using metal screws, they can be over tightened and crack the glass. I use a roofing style of screw with the built-in rubber gromets
Note: it will cut down on some of the sunlight and affect the overall wattage. If used in an array, remove it for a group or use a different charge controller.
The short video below shows how I made an adjusted solar tracker from common materials. It can be manually “steered” to follow the 10am – 6pm sun. It can be adjusted vertically and follow the winter or summer place of the sun. This particular solar tracker has been set up for my place. I wish I could get the sun from the morning until night, but, my neighbors trees block most of the morning sun. It would be silly to cut all the trees down. We both like the privacy and shade they offer.
• The solar panels can be “steered” to follow the sun from 12:00 pm to 6:00pm sun. There is a string attached to each “leg” of the panel side. Like the reins on a horse, you just pull one side to steer the panel towards the sun. Once the desired angle is found, the reins are secured to the tree to keep it from turning in the wind.
The solar panel mount can be adjusted for the suns place in the sky. For example, in the winter, the solar panel should be more vertical, like a 60 – 80 degree angle. It will shed the snow more easily and will get a few rays bouncing off the snow. When the summer finally arrives, the panel angle should be adjusted to 45 degrees.(Also depends on your place)
Note: A good guide to go from is to find the latitude you are at and subtract 15 degrees in the winter and add 15 degrees in the summer. Your local library, smart phone or Google Maps should be able to tell you the latitude.
• Yes, it’s mounted to a tree. Not the best plan, but it died a few years ago from the mountain pine beetle infestation. It can be mounted to a post or the side of a house.
• Aside from one of the legs getting caught on piles of snow. No significant problems and it has been in use for almost two seasons.
• Ideal to hold 1 – 3 home-made 63 watt solar panels.