An electro-active spherical balloon is susceptible to electromechanical instability which, for certain material models, can trigger substantial size change. Hence, the electro-active balloon can conveniently be employed for application as actuator or generator. Practical applications, however, require proper electrode protection from aggressive agents and electric safety. For this purpose, the active membrane can be sandwiched between two soft protective passive layers. In this paper, the theory of nonlinear electro-elasticity for heterogeneous soft dielectrics is applied to the investigation of the electromechanical response of multilayer electro-active spherical balloons, formed either by the active membrane only (single-layer balloon) or by the coated active membrane (multilayer balloon). Numerical results showing the influence of the soft passive layers on the electromechanical response of the active membrane are presented.