The expanding network of wireless sensors nodes for IoT applications requires autonomous and low power systems. Supercapacitors (SCs) and energy harvesters manage to replace batteries, offering power autonomy and lifetime. In this work, it is presented a power management system that uses a reconfigurable SC scheme as storage media that is capable to store sufficient energy, while presenting a rapid initial charging. The system is implemented in CMOS 0.35μm AMS technology and consists of a reconfigurable bank of SCs, which is the power source of the node, a control unit and a LDO providing constant output voltage for the wireless sensor node (WSN).