My first Solar Panel using New Cells (the seconds from a batch of cells).
You will be joining all 36 cells, in series, in 4 “strings” of 9.
· 1 900mm X 600mm sheet of plywood (enough for 2 panels).
· 1 tube Selleys All Clear.
· 45cm Red 25mm wire.
· 15cm Black 25mm wire.
· 1 Roll of very thin resin cored solder (60/40 tin to lead or 60/38/2 tin to lead to silver).
· 1 Resin Flux pen.
· A bit of “leftover” undercoat, some topcoat and a brush.
· A good soldering Iron. Adjustable voltage. About 48watt and the best you can afford. I bought one of these and it’s a ripper! http://cgi.ebay.com.au/TEMPERATURE-CONTROLLED-SOLDERING-IRON-STATION-48W-929B_W0QQitemZ170242190302QQihZ007QQcategoryZ29515QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
· A pair of tweezers and a pocket knife..
Paint your board and let it dry.
After it dries attach your junction box if using one.
*Prepare the cells for Soldering.
The backs of these cells have 4 positive contact points (called busses).
The front of the cells have 2 strips of negative contact point (also called busses).
Scratch the surface of the busses lightly with your pocket knife to remove oxidization and make the surface shiny.
*Pre heat your soldering iron to about 290deg C.
Tab only the back of the cells at this stage but do them all.
Apply flux to each bus before soldering.
Heat the clean, fluxed bus with the iron (about 290c) and apply a little solder. The solder should ball then spread a bit. Adjust your temperature until it does.
Do this to all 4 busses.
Take one of the tabs, place one end over the solder on a bus and heat with the iron. Apply a little more solder to the tip of the iron.
This will help the solder on the bus melt and adhere to bus and tab.
The tab should be also resting on the solder on the next bus. Do as above.
The “tail” of the tab will be sticking out one side of the cell.
Do the next tab in the same direction.
Repeat this step until all cells are tabbed.
Lay one of the tabbed cells (cell 1) on your workbench face up.
Prepare the front bus strips as you did the rear.
Pick up another cell (cell 2).
Place cell 2 face up on your workbench.
Place the tabs of cell 2 over the bus strips on the front of the first cell (cell 1).
Solder as with the rear..
Pick up another cell (cell 3).
Place the tabs of cell 3 over the prepared front bus strips of cell 2.
Repeat this until you have joined 9 cells (string 1).
Solder 2 tabs (or lengths of tab) to the front of cell 9 facing away from the string of cells.
Only do this with string 1.
This will become your negative out.
Carefully slide string 1 onto your (now dry) plywood.
Mark where the cells will sit the put 4 smallish “blobs” of silicone for each cell (so that the rear busses will sit on them).
This next bit will test your soldering and your nerve .
Lift the string of cells by the tabs and place it on the blobs of silicone. Lightly press each cell so that the cell is level and sitting a few mm clear of the plywood..
Repeat the above steps for the next 3 strings.
The strings need to be laid on the board “top to tail”, that is so that the negative (front) tabs of one string are adjacent to the positive (back) tabs of the next.
The positive tabs coming from the rear of string 4 are your positive out.
This diagram quite clearly shows why I’m not in graphic design……but it also shows how to lay your strings out.
Glue wires etc to board with blobs of silicone.
Allow 24 hours to dry.
Go outside and make lots of electricity.
My panels connect to a cheap controller, 85ah battery and 500watt inverter. They run fans and lights (for free!) and reduce my carbon footprint by a teeny bit.
I’ll add more DIY panels as soon as I can.
Most important Tip:
Your panel can only be as good as your worst soldered join allows. A bad join will restrict the flow of the good stuff.
Tip: Sellys All Clear melts when heated enabling the removal of cells from your board. Just apply heat to the top bus above the bottom bus a bit of a juggling trick to get all 4 hot at once but you can….then slide the cell off by gently pulling the tabs.
Tip: Don’t believe a lot of what you read in some of the tutorials online. Experience will soon show you which ones know what they’re talking about.
Tip: Join panels in parallel to maintain voltage (< >18v, your panels will peak at almost 20v) and increase wattage. Joining panels in series may fry your battery or blow a fuse in your control box.
Tip: Make your board/ply inflexible before you attach the cells. I cracked a cell when my ply bent.
Tip: Look after your soldering iron tip…..the user manual will tell you how.
Tip….last one I promise: Stay positive when you’re practicing on the scrap cells…..they’re much harder to solder than your good ones ( especially the backs….no busses). Once you’ve mastered them the worlds your oyster.
Enjoy the feeling of making your own power…..it’s a good thing to be doing.
All the best.