The series components have the same current through them but the voltage fluctuates. Generally, most LED lights contain a series-parallel combination. This is ideally perfect for reliability and lighting consistency. However, the wiring in series divides the net power supply between the LEDs. Wiring it in parallel means that each LED will get total voltage output by the power source. Therefore the suitability of the circuit depends on the type of voltage or power source it is connected with.