Because of their low voltage level, supercapacitors need arrangement with series connection in order to obtain voltage levels from few dozen to few hunderd of volts. As for batteries, devices have then to be defined to balance the voltages across each series connected components. This paper present the problematic of voltage sharing in a series connection of supercapacitors. It is generally described the way the balancing can be obtained easier with a coherent arrangement of the supercapacitors in their tank. Then, the main solutions for sharing the voltages with active devices are presented, detailed and compared, using a global modeling approach.