The invention concerns an electrical connection system for a percutaneous electrical connection between an electrical device (2) inside an animal body and an electrical device (3) outside said body, comprising a subcutaneous device (10) designed to be connected to internal electrical device (2), said subcutaneous device (10) comprising: an open housing (11) having at least one inner compartment (12), said compartment (12) being filled with a conductive material into which an electrical connection plug can be inserted, the conductive material of compartment (12) being further connected to connection means (5) designed to be connected to internal electrical device (2); a sealing membrane (13) for sealing housing (11), said sealing membrane (13) being formed of an insulating and flexible material designed for insertion of electrical connection plugs from outside housing (11) through said sealing membrane (13) to the conductive material of compartment (12); characterized in that housing (11) comprises alignment means (14) to facilitate positioning and to guide the insertion of electrical connection plugs into the corresponding conductive materials.