Because solar cells only produce a limited voltage and current, it is necessary to
connect them in series and parallel to achieve the required voltage and current.
Be sure to know your cells electrical specs to calculate your panel size and the
number of cells requires to achieve the desired voltage and current targets.
Tabbing the Cells
Before the cells are connected to form a solar panel, they have to be tabbed or wired
with a flat wire called tabbing wire which it is pre-tin with solder for ease the
To solder the tabbing wires use a soldering iron with sufficient heat, otherwise
the soldering process will be very difficult, it is also important to use a diagonal
or flat soldering iron tip to evenly apply the heat to the solar cell electrode buss
Before the cells are soldered be sure that they free of dirt and grease, could be
desirable to clean them with a soft fabric and alcohol before proceeding to solder
the tabbing wire, although the cleaning with alcohol could be optional, applying
solder flux to the buss electrode is a must to assure the good flow and quality of
the soldering. Fortunately applying the flux is a very easy process using flux pens
commercially available at very inexpensive price, just pass the pen as a regular
writing marker over the electrode buss wire, leave sufficient coverage.
Connecting Cells in Series
The cells connected in series must be connected following the polarity rule, the
negative electrode buss must be connected to the positive electrode buss as shown
in the figure, each one of the negative tabbing wire must be connected to positive
tabbing wire of the other cell and so on.
Three Cells Electrical Circuit Representation
Side view of the of the wiring of three cells, note that the upper cell side, must
be connected to the lower side of the next cell, this procedure must be followed
to all other cells connected in series.
Checking the Cells
It is recommendable to test each cell once is tabbed to avoid any disappointing surprise,
then each columns of series connected cells. It is a lot easier to fix any problem
at this stage that after you have completed the full panel assembly. Place the cell
exposed to sun light or a suitable strong lamp, connect a voltmeter to the tabbed
+ and - wires and check the reading, it must read at least 0.5 Volts.