Solar cells basics:

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150 3x6 Everbright Solar Cells ONLY Clipped Tabbed

Solar cells basics:

The front of the cells (blue side, aka Sunny side) has two thick white lines, called bus bars. They are the negative terminals of the cell. The back side, where the 6 square dots are, are positive terminals. Connect the tabbing wires from the bus bar of the first cell on one side to the three dots of on the back side of the next cell. That way you have a series connection. Repeat the process on the other side of the cells. In panel making you should connect all the tabbing wires on the front for all the cells first, then flip the cells over to solder the back side in a second step. Some solar cells such as SunPower cells have both positive and negative terminals at the back of the cells, but we don't have to worry about them. Most cells are negative on the front and positive on the back.

The white color bus bars (two thick lines) on front and the contact points on the back are made out of silver, and you should keep them intact. Apply flux on your them and the wires should bond. Do not scrape them off like you saw on some Youtube videos. They did that perhaps becaues the contacts are very very old and have heavy oxidation. The most you should do is to use a pencil eraser and rub on the contacts. But without cells, even this is not necessary. Just make sure that the contacts are clean, and always remember to apply some flux first before using your iron to solder the wires on the cells. Our cells are already coated with tin solder, so you don't need extra solder.