Additional power supply apparatus, in particular for electric vehicles or the like

The apparatus (1), in particular for electric vehicles or the like, comprises a combustion engine (2) and electricity generating means (3) suitable for generating electricity starting with the mechanical energy produced by the combustion engine (2), wherein the combustion engine (2) comprises an engine body (4) having two cylinders (5), two pistons (6) fitted sliding inside the cylinders (5), an engine shaft (7) associated with the engine body (4) axially rotatable and operatively connected to the pistons (6) and to the electricity generating means (3), wherein the cylinders (5) extend from the engine body (4) along respective directions substantially opposite one another, and wherein the engine shaft (7) is at right angles with respect to the cylinders (5) and has two extremities (7a, 7b) opposite and protruding with respect to the engine body (4) and wherein the electricity generating means (3) comprise two power generators (9) operatively connected to the opposite extremities (7a, 7b) respectively, of the engine shaft (7).