The invention relates to a system for charging at least one energy storing cell (5) in a controllable energy store (2) that is used to control and supply electric energy to an n-phase electric machine (1), wherein n>1. The controllable energy store (2) has n parallel energy supply branches (3-1, 3-2, 3-3), each of which has at least two serially connected energy storing modules (4), each said energy storing module comprising at least one electric energy storing cell (5) with a corresponding controllable coupling unit (6). The energy supply branches (3-1, 3-2, 3-3) can be connected to a reference bus (T-), and each energy supply branch can be connected to a phase (U, V, W) of the electric machine (1). The coupling units (6) bridge the respective corresponding energy storing cells (5) or connect same into the respective energy supply branch (3-1, 3-2; 3-3) dependent on control signals. The aim of the invention is to allow at least one energy storing cell (5) to be charged. This is achieved in that an external energy source (10) can be connected to a neutral point (S) of the electric machine (1) and to the reference bus (T-).