Solar Panels in Series To increase voltage, two or more solar panels can be connected in series. In series circuit, current is constant, total voltage = number of solar panels (Q) * Voltage per solar panel (V) For example: If two 6V 120mA panels are connected in series, the total power of 12V/120mA solar panels can be connected in parallel. If the voltage is sufficient to increase the current to reduce the charging time, two or more solar panels can be connected in parallel. In a parallel circuit, the voltage is constant, and the total current is equal to the number of solar panels (Q) * the current of each solar panel (I). For example, if two 6V, 120mA panels are connected in parallel, the total power is 6V/240mA series and parallel combination of solar panels. To increase the voltage and current at the same time, it is necessary to connect more than two solar panels in series and parallel. The total power of 8 6V,120mA solar panels is 12V/480mA. Two solar panels are connected in series and then combined to form 4 parallel circuits