Abstract: The present invention concerns an electrical or electronic apparatus, in particular welding machine or battery charger, comprising processing and controlling electronic means (M1, M2) connected to a sensing electronic means (S1, S1?, TR0, VT1, RT1, CT1, R8, CT2, Z1, Z2, Z3, Z4, Z5, Z6, Z7, R4, CT3, ST1, ST2, D12, Q1) from which it receives one or more detection signals of one or more electrical and/or physical quantities related to an apparatus operation, said processing and controlling electronic means (M1, M2) being capable to determine one or more conditions of apparatus operation on the basis of said one or more detection signals, the apparatus being capable to be power supplied through a plurality of terminals (F, N, GND) by a mains comprising a ground conductor to which a ground terminal (GND) of said plurality of terminals (F, N, GND) is connectable, the apparatus being characterised in that said sensing electronic means comprises or consists of a device (S1) for sensing a connection of the ground term

Abstract: A device for measuring a battery energy, in particular during charge/discharge of a battery, includes supply elements (3) apt to be connected to a battery (5) so as to make an electric current flow in/from the latter for one or more time intervals, and controlling and detecting elements (2), characterised in that the controlling and detecting elements (2) are apt to detect the energy stored in the battery (5) during a time period including at least one portion of the one or more time intervals.