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Build a 60 Watt Solar Panel
by mdavis19 on September 11, 2008
Table of Contents
intro: Build a 60 Watt Solar Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
step 1: Buy some solar cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
step 2: Build the box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
step 3: Finishing the box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
step 4: Paint the box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
step 5: Prepare the solar cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
step 6: Solder the solar cells together . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
step 7: Glue down the solar cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
step 8: Interconnect the strings of solar cells and test the half panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
step 9: Install the half panels in the box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
step 10: Interconnect the two half panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
step 11: Install the blocking diode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
step 12: Run wires outside and put the Plexiglass covers on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
step 13: Add a plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
step 14: The completed panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
step 15: Testing the solar panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
step 16: Using the solar panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
step 17: Counting the cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
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Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
/>intro: Build a 60 Watt Solar Panel
Several years ago I bought some remote property in Arizona. I am an astronomer and wanted a place to practice my hobby far away from the terrible light pollution found
near cities of any real size. I found a great piece of property. The problem is, it's so remote that there is no electric service available. That's not really a problem. No
electricity equals no light pollution. However, it would be nice to have at least a little electricity, since so much of life in the 21st century is dependent on it.
I built a wind turbine to provide some power on the remote property (will be another instructable in the future). It works great, when the wind blows. However, I wanted

more power, and more dependable power. The wind seems to blow all the time on my property, except when I really need it too. I do get well over 300 sunny days a year
on the property though, so solar power seems like the obvious choice to supplement the wind turbine. Solar panels are very expensive though. So I decided to try my
hand at building my own. I used common tools and inexpensive and easy to acquire materials to build a solar panel that rivals commercial panels in power production,
but completely blows them away in price. Read on for step by step instructions on how I did it. Visit my web site for more details on this and and other projects at
/>step 1: Buy some solar cells
I bought a couple of bricks of 3 X 6 mono-crystalline solar cells. It takes a total of 36 of these type solar cells wired in series to make a panel. Each cell produces about
1/2 Volt. 36 in series would give about 18 volts which would be good for charging 12 volt batteries. (Yes, you really need that high a Voltage to effectively charge 12 Volt
batteries) This type of solar cell is as thin as paper and as brittle and fragile as glass. They are very easily damaged. The Ebay seller of these solar cells dips stacks of 18
in wax to stabilize them and make it easier to ship them without damaging them. The wax is quite a pain to remove though. If you can, find cells for sale that aren't dipped
in wax. Keep in mind though that they may suffer some more damage in shipping. Notice that these cells have metal tabs on them. You want cells with tabs on them. You
are already going to have to do a lot of soldering to build a panel from tabbed solar cells. If you buy cells without tabs, it will at least double the amount of soldering you
have to do. So pay extra for tabbed cells.
I also bought a couple of lots of cells that weren't dipped in wax from another Ebay seller. These cells came packed in a plastic box. They rattled around in the box and
got a little chipped up on the edges and corners. Minor chips don't really matter too much. They won't reduce the cell's output enough to worry about. These are all
blemished and factory seconds anyway. The main reason solar cells get rejected is for chips. So what's another chip or two? All together I bought enough cells to make 2
panels. I knew I'd probably break or otherwise ruin at least a few during construction, so I bought extras.
Image Notes
1. Cells dipped in wax to prevent damage in shipping. The wax is a pain to
remove
Image Notes
1. Solar cells in a plastic box. They rattled around and the edges got chipped in
shipping.
/>step 2: Build the box
So what is a solar panel anyway? It is basically a box that holds an array of solar cells. So I started out by building myself a shallow box. I made the box shallow so the
sides wouldn't shade the solar cells when the sun comes at an angle from the sides. It is made of 3/8 inch thick plywood with 3/4 X 3/4 pieces of wood around the edges.
The pieces are glued and screwed in place. This panel will hold 36 3 X 6 inch solar cells. I decided to make 2 sub-panels of 18 cells each just so make it easier to
assemble. I knew I would be working at my kitchen table when I would be soldering the cells together, and would have limited work space. So there is a center divider
across the middle of the box. Each sub-panel will fit into one well in the main panel.
The second photo is my sort of back of the envelope sketch showing the overall dimensions of the solar panel. All dimensions are in inches (sorry you fans of the metric
system). The side pieces are 3/4 by 3/4 and go all the way around the edges of the plywood substrate. also a piece goes across the center to divide the panel into two

sub-panels. This is just the way I chose to do it. There is nothing critical about these dimensions, or even the overall design.
Image Notes
1. Tools required to build the box were a power miter box saw, hand drill and
screw gun.
step 3: Finishing the box
Here is a close-up showing one half of the main panel. This well will hold one 18 cell sub-panel. Notice the little holes drilled in the edges of the well. This will be the
bottom of the panel (it is upside down in the photo, sorry). These are vent holes to keep the air pressure inside the panel equalized with the outside, and to let moisture
escape. These holes must be on the bottom of the panel or rain and dew will run inside. There must also be vent holes in the center divider between the two sub panels.
Next I cut two pieces of masonite peg-board to fit inside the wells. These pieces of peg-board will be the substrates that each sub-panel will be built on. They were cut to
be a loose fit in the wells. You don't have to use peg-board for this. I just happened to have some on hand. Just about any thin, rigid and non-conducting material should
work.
To protect the solar cells from the weather, the panel will have a plexiglass front. In the third picture, two pieces of scrap plexiglass have been cut to fit the front of the
panel. I didn't have one piece big enough to do the whole thing. Glass could also be used for this, but glass is fragile. Hail stones and flying debris that would shatter
glass will just bounce off the plexi. Now you can start to see what the finished panel will look like.
Image Notes
1. Vent/drainage holes in bottom of panel.
2. More vent/drainage holes in the center divider.
/>step 4: Paint the box
Next I gave all the wooden parts of the panel several coats of paint to protect them from moisture and the weather. The box was painted inside and out. The type of paint
and color was scientifically chosen by shaking all the paint cans I had laying around in my garage and choosing the one that felt like it had enough left in it to do the whole
job.
The peg-board pieces were also painted. They got several coats on both sides. Be sure to paint them on both sides or they will warp when exposed to moisture. Warping
could damage the solar cells that will be glued to them.
Image Notes
1. Be sure to paint both sides or the panels will warp with changes in humidity.
step 5: Prepare the solar cells
Now that I had the structure of the panel finished, it was time to get the solar cells ready
As I said above, getting the wax off the cells is a real pain. After some trial and error, I came up with a way that works fairly well. Still, I would recommend buying from
someone who doesn't dip their cells in wax.
This photo shows the complete setup I used. My girlfriend asked what I was cooking. Imagine her surprise when I said solar cells. The initial hot water bath for melting the

wax is in the right-rear. On the left-front is a bath of hot soapy water. On the right-front is a bath of hot clean water. All the pots are at just below boiling temperature. The
sequence I used was to melt the bricks apart in the hot water bath on the right-rear. I'd tease the cells apart and transfer them one at a time to the soapy water bath on
the left-front to remove any wax on the cell. Then the cell would be given a rinse in the hot clean water on the right-front. The cells would then be set out to dry on a towel.
You should change the water frequently in the soapy and rinse water baths. Don't pour the water down the sink though, because the wax will solidify in your drains and
clog them up. Dump the water outside. This process removed almost all the wax from the cells. There is still a very light film on some of the cells, but it doesn't seem to
interfere with soldering or the working of the cells.
Don't let the water boil in any of the pans or the bubbles will jostle the cells against each other violently. Also, boiling water may be hot enough to loosen the electrical
connections on the cells. I also recommend putting the brick of cells in the water cold, and then slowly heating it up to just below boiling temperature to avoid harsh
thermal shocks to the cells. Plastic tongs and spatulas come in handy for teasing the cells apart once the wax melts. Try not to pull too hard on the metal tabs or they may
rip off. I found that out the hard way while trying to separate the cells. Good thing I bought extras. More details on this step can be found on my web site at
/> />Image Notes
1. Pot of hot water to melt the wax on the cells.
2. Pot of hot soapy water to remove wax residue from the cells.
3. Pot of warm clean water to give the cells a final rinse.
Image Notes
1. Wax-free cells drying on a towel.
step 6: Solder the solar cells together
I started out by drawing a grid pattern on each of the two pieces of pegboard, lightly in pencil, so I would know where each of the 18 cells on them would be located. Then
I laid out the cells on that grid pattern upside-down so I could solder them together. All 18 cells on each half panel need to be soldered together in series, then both half
panels need to be connected in series to get the desired voltage.
Soldering the cells together was tricky at first, but I got the hang of it fairly quickly. Start out with just two cells upside-down. Lay the solder tabs from the front of one cell
across the solder points on the back of the other cell. I made sure the spacing between the cells matched the grid pattern. I continued this until I had a line of 6 cells
soldered together. I then soldered tabs from scrapped solar cells to the solder points on the last cell in the string. Then I made two more lines of 6 cells.
I used a low-Wattage soldering iron and fine rosin-core solder. I also used a rosin pen on the solder points on the back of the cells before soldering. Use a real light touch
with the soldering iron. The cells are thin and delicate. If you push too hard, you will break the cells. I got careless a couple of times and scrapped a couple of cells. More
details on this step can be found on my web at />Image Notes
1. Solder the tabs from the front of one cell onto the pads on the back of the next
cell.
/>step 7: Glue down the solar cells
Gluing the cells in place proved to be a little tricky. I placed a small blob of clear silicone caulk in the center of each cell in a six cell string. Then I flipped the string over

and set in place on the pencil line grid I had laid out earlier. I pressed lightly in the center of each cell to get it to stick to the pegboard panel. Flipping the floppy string of
cells is tricky. Another set of hands may be useful in during this step.
Don't use too much glue, and don't glue the cells anywhere but at their centers. The cells and the panel they are mounted on will expand, contract, flex and warp with
changes in temperature and humidity. If you glue the cells too tightly to the substrate, they will crack in time. gluing them at only one point in the center allows the cells to
float freely on top of the substrate. Both can expand and flex more or less independently, and the delicate solar cells won't crack.
Next time I will do it differently. I will solder tabs onto the backs of all the solar cells. Then I will glue all the cells down in their proper places. Then I will solder the tabs
together. It seems like the obvious way to go to me now, but I had to do it the hard way once to figure it out.
Here is one half panel, finally finished.
step 8: Interconnect the strings of solar cells and test the half panel
Here I used copper braid to interconnect first and second strings of cells. You could use solar cell tabbing material or even regular wire. I just happened to have the braid
on hand. There is another similar interconnection between the second and third strings at the opposite end of the board. I used blobs of silicone caulk to anchor the braid
and prevent it from flopping around.
The second photo shows a test of the first half panel outside in the sun. In weak sun through clouds the half panel is producing 9.31 Volts. YAHOO! It works! Now all I
had to do is build another one just like it.
Once I had two half panels complete, I could install them in their places in the main panel frame and wire them together.
/>Image Notes
1. Copper braid interconnecting two strings of cells.
Image Notes
1. 9.31 Volts in weak sunlight. Wooo Hooo, it works!
step 9: Install the half panels in the box
Each of the half panels dropped right into their places in the main panel frame. I used four small screws (like the silver one in the photo) to anchor each of the half panels
in place.
Image Notes
1. Screw (1 of 4) holding one of the half panels in place in the box.
2. Screw holding plexiglass cover in place
step 10: Interconnect the two half panels
Wires to connect the two half panels together were run through the vent holes in the central divider. Again, blobs of silicone caulk were used to anchor the wire in place
and prevent it from flopping around.
/>Image Notes
1. blobs of silicone to secure wires and prevent them from flopping around.

2. wires passed through the vent holes in the center divider to connect the two half panels together.
step 11: Install the blocking diode
Each solar panel in a solar power system needs a blocking diode in series with it to prevent the panel from discharging your batteries at night or during cloudy weather. I
used a Schottky diode with a 3.3 Amp current rating. Schottky diodes have a much lower forward voltage drop than ordinary rectifier diodes, so less power is wasted.
Every Watt counts when you are off-grid. I got a package of 25 31DQ03 Schottky diodes on Ebay for only a few bucks. So I have enough left-overs for lots more solar
panels
My original plan was to mount the diode inline with the positive wire outside the panel. After looking at the spec-sheet for the diode though, I decided to mount it inside
since the forward voltage drop gets lower as the temperature rises. It will be warmer inside the panel and the diode will work more efficiently. More silicone caulk was
used to anchor the diode and wires.
Image Notes
1. Blocking diode soldered in line with the positive output wire.
step 12: Run wires outside and put the Plexiglass covers on
I drilled a hole in the back of the panel near the top for the wires to exit. I put a knot in the wires for strain relief, and anchored them in place with yet more of the silicone
caulk.
It is important to let all the silicone caulk cure well before screwing the plexiglass covers in place. I have found through past experience that the fumes from the caulk may
leave a film on the inside of the plexiglass and on the cells if it isn't allowed to thoroughly cure in the open air before screwing on the covers.
And still more silicone caulk was used to seal the outside of the panel where the wires exit.
/>Image Notes
1. Knot in the output wires for strain relief.
Image Notes
1. Seal the hole where the wires exit with silicone caulk.
step 13: Add a plug
I added a polarized two-pin Jones plug to the end of the panel wires. A mating female plug will be wired into the charge controller I use with my home-built wind turbine so
the solar panel can supplement it's power production and battery charging capacity.
Image Notes
1. Polarized 2-prong Jones plug on output wires.
step 14: The completed panel
Here is the completed panel with the plexiglass covers screwed into place. It isn't sealed shut yet at this point. I wanted to wait until after testing it because was worried
that I might have to get back inside it if there were problems. Sure enough, a tab popped off one of the cells. Maybe it was due to thermal stresses or shock from
handling. Who knows? I opened up the panel and replaced that one cell. I haven't had any more trouble since. I will probably seal the panel with either a bead of silicone

caulk, or aluminum AC duct tape wrapped around the edges.
/>Image Notes
1. Finally finished. Ready for Testing.
step 15: Testing the solar panel
The first photo shows the Voltage output of the completed panel in bright winter sunlight. My meter says 18.88 Volts with no load. That's exactly what I was aiming for.
In the second photo I am testing the current capacity of the panel, again in bright winter sunlight. My meter says 3.05 Amps short circuit current. That is right about what
the cells are rated for. So the panel is working very well.
Image Notes
1. 18.88 Volts in bright Sunlight (no load).
Image Notes
1. 3.05 Amps short circuit current in bright Sunlight.
step 16: Using the solar panel
Here is a photo of the solar panel in action, providing much needed power on my remote Arizona property. I used an old extension cord to bring the power from the panel
located in a sunny clearing over to my campsite under the trees. I cut the original ends off the cord and installed Jones plugs. You could stick with the original 120V
connectors, but I wanted to make sure there was absolutely no chance of accidentally plugging the low-Voltage DC equipment into 120V AC.
I have to move the panel several times each day to keep it pointed at the sun, but that isn't really a big hardship. Maybe someday I will build a tracking system to
automatically keep it aimed at the sun.
More details on the electrical system can be found on my web site at
/>step 17: Counting the cost
So how much did all this cost to build? Well, I saved all the receipts for everything I bought related to this project. Also, my workshop is well stocked with all sorts of
building supplies and hardware. I also have a lot of useful scrap pieces of wood, wire and all sorts of miscellaneous stuff (some would say junk) laying around the shop.
So I had a lot of stuff on hand
already. Your mileage may vary.
Part Origin Cost
Solar Cells Ebay $74.00*
Misc. Lumber Homecenter Store $20.62
Plexiglass Scrap Pile $0.00
Screws & Misc. Hardware Already on hand $0.00
Silicone Caulk Homecenter Store $3.95
Wire Already on hand $0.00

Diode Ebay $0.20+
Jones Plug Newark Electronics $6.08
Paint Already on hand $0.00
Total $104.85
Not too bad. That's a fraction of what a commercially made solar panel with a comparable power output would cost, and it was easy. I already have plans to build more
panels to add to the capacity of my system.
Visit my web site for more details on this and my other projects at
* I actually bought 4 lots of 18 solar cells on Ebay. This price represents only the two lots that went into building this panel. Also, the price of factory second solar cells on
Ebay has gone up quite a lot recently as oil prices have skyrocketed.
+ This price represents 1 out of a lot of 25 diodes I bought on Ebay for $5.00.
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Comments
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DIYDragon says:
Dec 9, 2008. 9:07 AM REPLY
"The type of paint and color was scientifically chosen by shaking all the paint cans I had laying around in my garage and choosing the one that felt like it had
enough left in it to do the whole job."
Nothing quite like scientific deduction. haha
I've always been very interested in solar energy. I keep waiting for somebody to come a long, and make it much cheaper, and applicable. I'm watching a
company who claims they can make this happen, but no word on their work so far. Oh well!
braddd says:
Dec 9, 2008. 1:11 PM REPLY
What company might this be? :D
DIYDragon says:

Dec 16, 2008. 12:51 PM REPLY
They're called Sunrgi.
sammilo says:
Nov 28, 2008. 12:08 PM REPLY
I like the bits and i will like to get the ideas mor an dmore
panstar1 says:
Nov 26, 2008. 1:54 AM REPLY
I like your design ,it is a lot more practical then others I have seen on this site. Even though solar panels are a pain in the butt ,they beat carrying gallons of
gas for a little unforgiving noise box for hours on end. why they don't sell them with liquid cooled engines to cut down on half of the noise ? But the solar
panels still cost you at lest 78 American which is some where around $100 + CND which makes it expensive to build b/c you can buy a ready made one ( I
can't remember the rating I think 18 + ) for less then 90 dollars on sale which is a less hair pulling aproch for some ! also shipping is also a big tie breaker as
well ,but the price of gas has been rising so if you like playing with delicate items then why not ! The only bad part is the expensive batterys we have some
from that were used for power back and are really heavy but have a lot of juice iron lead I think they said on them the problem lie in having enough power to
charge them do you have such problem ? & is there a special angle the panel's have to be placed at & would having them follow the sun make more power
for the fuss ?
/> fulcrum says:
Oct 29, 2008. 3:02 PM REPLY
There are three types of camping, and they all have their place. Backpack camping where all your gear is ultra-light, Car camping, where there is mor
"family" heavier gear, and trailer camping, especially "boondocking" where there is no AC for your trailer. I have a very similar system with twin 3o Watt
panels, two inverters (one small, one large, and two 90 Amp/Hour batteries. If I'm on the 'grid', I still use my solar input, and let a charger kick in after sunset.
TFrosty says:
Nov 11, 2008. 9:04 AM REPLY
Where did you get your 90AH batteries? Do you know how much a 7AH can be used for????
fulcrum says:
Nov 11, 2008. 10:11 AM REPLY
The 90 A/H batteries are lead acid "Car Battery' size Deep Discharge recreation vehicle types. Cost is the same or less than a car battery.
NOTE: Do not use standard car batteries for this application, they are designed for heavy starter currents, and will die prematurely if you trickle
current in and out of them over extended periods. Also "starter" car batteries are NOT designed to be discharged to under about 80 to 85%. Deep
discharge will kill them quickly.
A fully charged 7 ampere-hour battery will light a ten Watt bulb for four and a half hours, or a thermoelectronic cooler for about an hour, max. It will

live for about 3 to 6 years, whether you use it or not!.
TFrosty says:
Nov 11, 2008. 12:05 PM REPLY
Thanks!!! what is the formula you used to calculate the 7AH 12V?
fulcrum says:
Nov 11, 2008. 3:16 PM REPLY
Multiply the numbers for power. volts times amps equals Watts. In this case its 7x12=84 Watt/Hours. But you can't get at the last 20% of the
juice, because the voltage is too low to push enough current through the load as the battery dies, and it's bad for the battery not to leave a
remaining charge. you can do this in an emergency, but it will shorten the life of the battery. Yo can rely on about 65 Watt/Hours in this case,
so a 50 Watt cooler will run for 65/50 hours. An hour and a bit. A 10 Watt lamp would last for 65/10 Hours, That's a theoretical 6.5 hours on a
brand new, fully charged battery. Unfortunately, a fully charged 2-year-old 7AH will be closer to 5AH, so the numbers are reduced to allow for
real-world performance. Dropping this by 20% only allows you to design for a 40 Watt/Hour delivery. Admittedly, the numbers are rather
conservative, but if the system were to be used in a life or death situation, these numbers would be safe. For general use, I would call it closer
to 55 Watt/Hours.
fulcrum says:
Nov 11, 2008. 10:19 AM REPLY
Just to clarify for Tfosty, The batteries I am using are type 24 classified. You can get type 27 (larger size) batteries with 120 A/H capacity.
Starter batteries shouldn't be discharced to less than 15% from full, leaving a minimum of 85% charge!!
dalecarlile says:
Sep 18, 2008. 2:46 PM REPLY
FYI, Silicone contains an acid and can result in electrical connections corroding over time from the outgassing. Not all of the acid evaporates in the initial
curing. So I would recommend keeping it to a minimum and opening the panel or venting it very well after it is hot. I found that some silica gel packs with the
color indicators for moisture work very well at keeping condensation out of panels I have built. I also learned to use a voltage regulator to limit the charging
voltage to a maximum of 14.2 volts on a 12 volt battery. Batteries get cooked/damaged from excessive charging voltages. I also use anderson pole
connectors on my DC Systems.
wupme says:
Sep 19, 2008. 12:05 AM REPLY
Didn't knew that, and whats about aquaristik silicone, used to build fish tanks?
As far as i know, its free of that stuff after it cured.
dacarls says:

Oct 16, 2008. 12:40 PM REPLY
Wupme,
Down lower you describe an antibiotic soap. Please share name and if its prescription, as I have the same problem: hair follicle inflammation
problem. I've been thru coal-oil stuff, various antibiotic soaps, even phisohex, benzoyl peroxide treatment, 3% aqueous peroxide for years. I might
have gotten some of it in the African jungle (Mali, this is not a joke). Soap every day is the best.
This has been a long term problem (many years). Now I have to go out and finish my solar cell array Suggestions welcome.

dalecarlile says:
Sep 19, 2008. 7:57 AM REPLY
Put some on a piece of foil and let it cure overnight. Then place it in a sealed jar. Place the jar in the Sun for a day and then check for a thin film of
out gassed stuff on the inside of the jar. In a low temperature environment, you will get less out gassing per unit of time.
kadris3 says:
Sep 18, 2008. 3:27 PM REPLY
batteries fry a lot lower than 14.2vdc. 13.8vdc fm a car system will boil them good . you need 13.2 vdc for a float charge to keep the batteries fm boiling.
at 13.2vdc or 13.25vdc they won't boil, but will charge up nicely. if u use full array power to charge them it must be reduced as the batteries reach full
charge. they must be switched to the float voltage to save electrolite. as they get almost dry the hydrogen in them blows. this can occur with as little as a
one(1) amp charge.
good 'structable. i was never that brave. those things are as brittle as sugar glass(used in movies). the alternative cost 4 or 5 times as much as your
investment. many people like a little power in the woods; i.e., ham radio, some light, astronomy, camera, glucose meters, etc.
gater clips are less expensive than power pole connex which while tidy, and pushed by ARRL, are overrated.
/> ac7ss says:
Nov 1, 2008. 5:17 PM REPLY
Yes, powerpoles are over-rated. Most people will never need a 45 amp bi-polar connector in .21 inches square, however they do make a handy 12
volt standard for your personal grid. I find that few connectors work as well, can be easily connected/disconnected, have self cleaning contacts, and
can be panel mounted as the powerpoles.
static says:
Sep 23, 2008. 3:42 PM REPLY
I haver never read the ARRL adopting the power poles as a standard, as they did the Molex/RS connectors. That's not say individual ARES groups
haven't adopted them a a standard connector for the sake of equipment interchangeability. Power poles can be quite inexpensive if a groups get
together and makes large purchase.

kadris3 says:
Sep 23, 2008. 4:30 PM REPLY
ARRL IS definitely pushing them for emergency service. i didn't care for them as they tend to disconnect too easily for my liking. also they want all
to have them so we can share power in an emergency deployment. if i come to a disaster prepared to operate and someone else comes w a
dead battery in his walkie it is my responsibility to take care of his need as well as mine???? i don't think so.
it's just another would be helper who becomes part of the problem. these are given runner duty or sent home.!!!!!!!!!!!
wally33 says:
Oct 5, 2008. 6:25 PM REPLY
I heard this guy talking about this project on an adelaide radio station down in australia
guitarman63mm says:
Sep 23, 2008. 2:13 PM REPLY
I would like to mention, folks, something I read off an eBay auction.
There's a seller who sellers 60 chipped cells, and claims that each cell puts out about .55 volts. Round that off to .5
He said that each cell gets about .25 to .5 amps each. Round that off to .3, because I think that's a liberal estimate.
Now then, that leaves you with 30 volts, and 18 amps. Plug that into that great little formula james joule cooked up. P=V(I)
P being watts, V being volts, I being amps.
P = 30(18) = 540 watts
Meaning that one large panel could be split and put into parallel, yielding 15 volts and 36 amps, no? Is it not possible to hook that up to a strong 12v power
inverter and run strong appliances off of it?
I feel that I must have missed something rather obvious, as no one else has brought this up before me. Did I miscalculate?
Please advise guys! (pardon the rhyme )
mdavis19 says:
Sep 27, 2008. 6:07 AM REPLY
If the cells are wired in series. The voltage adds but the current is limited to the output of the smallest cell in the array. So it would be 30 Volts at .3 Amps
If instead they are wired in parallel it would be .5 Volts at about 18 Amps. Either way, you get a total of 9 Watts out of those 60 cells. The best application
would probably be to make two banks of 30 cells producing about 15 Volts at about .6 Amps to charge a 12 Volt battery. The total is still 9 Watts though.
guitarman63mm says:
Sep 27, 2008. 7:42 AM REPLY
I live in Florida, and when your car heats up to 95? daily, you look for some sort of way out. My idea was to get a small air conditioner->A/C Timer-
>Inverter->Separate car battery. Then, it would be set to kick on about 30 minutes before I got out of class, so my car would be like an icebox for me.

Plausible? Is there a way to increase wattage without increasing voltage/decreasing current?
I have rack mounts on top of my microbus, I was simply going to place the panels up top, secure them, and have at it.
killrsheep says:
Oct 2, 2008. 12:08 PM REPLY
some guys at college did that to get their degree they placed a big cell on the roof of a 4 door sedan and secured it in place with fiberglass, but
they placed 2 fans in the car, one pushing air inside the car from the front (engine compartment i suppose), and another fan pushing air out to the
trunk space but thay made a big mistake IMO they used an inverter! (bcuz they used a 24V AC fan i have no idea where theyd get such a
thing) there is such a thing as a DC FAN (and they are more common than AC's) and using an inverter is wasting energy , its entirely possible
in a microbus, and using a charge control for the batteries.
I dont know if an air conditioner would need too much power but fans are an easy solution Good luck!
killrsheep says:
Oct 2, 2008. 12:11 PM REPLY
by the way one way to increase your available power would be getting either more modules or more batteries i guess, the only thing is that
more batteries will require more charging time
conundrum1222 says:
Sep 28, 2008. 2:15 PM REPLY
Okay just a quick question, have you ever tested to see what the temperature gets up to in the box during the day? I assume in Arizona it could get to be
rather warm, just wondering if this additional thermal energy could be captured and harnessed for something?
/> tuckwood123 says:
Sep 30, 2008. 2:34 PM REPLY
i've seen that the hotter it is, the worse it works- you can check out the info at youtube, its in conjunction with google.
ReCreate says:
Sep 30, 2008. 8:31 PM REPLY
you could put some sort of fan in the back
A few 12 volt ones under a voltage regulator?
tuckwood123 says:
Oct 1, 2008. 1:23 AM REPLY
i guess you could, but surley using energy to cool down the panel will make the task useless. plus you would need more circuit wizardry to stop
the fans blowing on a cool day On the google video the guy throws a bucket of water over the panel and booyah- job done. Just to be honest,
the power loss for hot weather is about 10%. also, every year the panel becomes less efficient by 0.25% (if we are to believe everything endorsed

by google)
Lego man says:
Sep 14, 2008. 4:04 PM REPLY
where in Arizona? I live in Kingman and there is alot of open space here.
BRJones says:
Sep 29, 2008. 9:44 PM REPLY
Have you built one of these Lego? I too live in Kingman and want to build solar panels for my place. And if you have made them then I know who I can
ask that is just around the corner.
mdavis19 says:
Sep 27, 2008. 6:11 AM REPLY
My property is in rural Apache county. About midway between St. Johns and Snowflake, and maybe 30 miles South of the Petrified Forest National Park
(as the crow flies).
NetReaper says:
Sep 29, 2008. 8:11 AM REPLY
What if you set them up in a 3d ring pattern, put it up on a poll, and put lots of mirrors around it? would that give you more power?
cowgomoo says:
Sep 29, 2008. 8:20 PM REPLY
helllllll yes and i say do it and make an instructable
Sunkicked says:
Sep 22, 2008. 1:16 PM REPLY
Great Instructable! My only question is about purchasing the cells. Is there a commercial vendor that sells these cells (sorry for that choice of words)? I've
found that when people post that they gathered their supplies from eBay it can be maddeningly hard to find another auction for the same material. Thanks!
static says:
Sep 23, 2008. 8:10 PM REPLY
I'm not a skilled ebayer, but can't you configure it to send email alerts, when desired items are posted for sale?
xenor says:
Sep 27, 2008. 1:36 AM REPLY
You can create a custom search that will email you when a matching listing appears, but it's only as good as the search you create.
Sunkicked says:
Sep 27, 2008. 11:00 PM REPLY

I love this site. Ask a question and have an answer within a day or two. Thanks guys!
DavyBaby says:
Sep 18, 2008. 11:36 PM REPLY
Well Done!!
Maybe swop the connectors and have the female one connected to the "live" side ie the cells.
I am inspired to build.
mdavis19 says:
Sep 27, 2008. 5:52 AM REPLY
I put the male end on the solar panel and the female end on the cable to the batteries and charge controller because if the cable to the batteries shorted,
it could potentially have several hundred amps flowing through the short circuit. That would be bad.
/> The Bottomless Paddling Pool says:
Sep 17, 2008. 5:34 AM REPLY
This Instructable is great and very inspiring and I understand that you need electricity for your astronomy gear, but I don't understand why everyone else is
going on about using electricity while camping. I also don't believe that camping is camping if you are with your car. Maybe it's just the culture of the outdoors
in my country, but it seems a little weird. I thought the purpose of camping was to get away from things like electricity, cars, TV's, etc
Can someone explain these cultural differences to me, or is it just some people who do this?
mdavis19 says:
Sep 27, 2008. 5:38 AM REPLY
Photography is one of my hobbies. Digital cameras eat through batteries like crazy. So I use rechargable batteries, but then I need a power source for
the charger. I also need power for my laptop computer so I can dump images from the camera when the memory card gets full, and then edit the images.
I like to have a radio and MP3 player with me while camping (I don't need television, and specifically go on vacation sometimes just to get away from the
idiot box). My electric razor is a must have or I start looking like Grizzly Adams after a couple of days (beards are itchy), but of course it requires power
too. My cell phone needs charging after a while, etc. But the camping power requirements really go up when I take my girlfriend along. She likes to watch
TV and DVDs. She also has her own slew of power hungry devices. and she won't be happy on our camping trips until I can make enough power for her
to use her blow dryer. That aint gonna happen any time soon.
static says:
Sep 23, 2008. 3:07 PM REPLY
As they say different stokes for different folks. For some "camping" means getting away from the routine grind A dead end trying to explain cultural
differences. They are always going to be there, as long as they don't intrude into your space, why sweat them?
wupme says:

Sep 18, 2008. 11:59 PM REPLY
I don't take things like TV's or stuff with me when i go Camping.
But its nice to have at least a battery powered light for the night. Flashlights and the campingfire sometimes are just not enough. And maybee i need to
recharge the flashlight.
Because if would go camping, then a whole week at least (don't wanna waste to much batteries )
But beside that, yeah you don't need an power source. I don't understand why people take TVs, Radios and other electrical sh** with them.
I just need my food, something to sleep, maybee a small gas cooker, and my handy utility knife.
jgullo29 says:
Sep 18, 2008. 11:03 AM REPLY
Hello Bottomless,
This is just the preference of some people. I would have to agree with you. When I go camping, I make sure I am as far from civilization as possible. To
be honest, our society as a whole has become very dependent so it is actually quite rare to find people really "roughing" it in the outdoors. I only have
one friend that will go to those lengths with me.
Where do you live?
Joey
craz meanman says:
Sep 23, 2008. 3:21 PM REPLY
like you just walk around with only some tools? i was thinking of doing that this summer, but didn't find the time, or a person to with (you would really
need one for your first time).
The Bottomless Paddling Pool says:
Sep 18, 2008. 6:08 PM REPLY
I live in New Zealand. Here you're either roughing it or it's not camping, I have barely ever seen another Kiwi with more gadgets other than a gas
cooker, a torch and navigation equipment (cellphones don't work in unpopulated areas, so there's no point in taking one). It's a little different if you're
on a rock climbing camp or something like that, then you understandably need extra gear. We also go on outdoor trips with cars and other items of
comfort such as showers, stereo, etc but I have never heard of it as camping, more of a holiday from routine. It is usually a family/friends affair
where a small community of tents, outdoor kitchens, camper-vans, utes and so on are set up on some remote idyllic beach and everyone spends
several weeks away from what they would normally do just enjoying the freedom. I've done it quite a lot, never considered it camping, though.
Sam Grove says:
Sep 18, 2008. 11:02 AM REPLY
I thought the purpose of camping was to get closer to nature, not to escape comfort.

If I go two days without a shower, I get oily and my scalp gets itchy, so I like to shower when camping if possible.
Perhaps you have dry skin, so don't experience this discomfort.
wupme says:
Sep 19, 2008. 12:02 AM REPLY
Thats the only problem i would have.
My hair gets oily and itchy really fast, i have to at least wash my hair with my special shampoo every 2nd day (wich the doctor orderd me to do).
But there are also some soaps wich are enviroment friendly, and don't polute the water to at least wash your hands and some sensitive areas.
/> Crucio says:
Sep 21, 2008. 8:33 PM REPLY
You can use little apple cider vinegar and baking soda as a green way to wash oily hair and skin on camping trips or even at home, everyday.
E.g., />view all 111 comments