A modular device for accumulation and delivery of electrical energy, including a structure including a plurality of shelving, an air conditioning system, and at least one bi-directional electronic multi-level converter defining a transformerless AC/alternating current output and including three three-phase legs connected to the output and each including a plurality of modules connected in series, a plurality of inductors arranged on a respective output line from the legs, and a firmware control device to modify current and voltage output from the modules. Each of the modules includes a first stage AC output including an IGBT device, isolated to ground, capable of connecting in series with the other modules of a respective leg and capable of generating an output voltage waveform, a second DC/DC conversion stage defining an input, and at least one battery connected to the input. The battery is an electric vehicle battery (EVB).