Connection platform for a functional unit of an electrical cell comprising a support provided on a first side with a set of power supply clamps and a set of output clamps, each clamp being open towards the outside of the support and arranged so as to be able to be pinned on a rigid conductor element (14, 20) of the cell and unpinned from said element upon a translational movement in a first direction at right angles to at least a part of the first side, further characterized by a block of auxiliary contacts comprising: - a frame that is fixed relative to the support; - a first and a second connector (62, 64) each comprising contacts of complementary forms, translationally mobile in a first direction relative to one another between an open position of disconnection between their contacts and a closed test position in which the contacts of the first connector are closed with the contacts of the second connector, the two connectors (62, 64) being translationally mobile in the first direction relative to the frame between a power disconnection position and a power connection position; - a positive locking device for the second connector comprising blocking means that are mobile between a locking position in which the second connector and the frame are locked in the power disconnection position and an unlocking position in which the relative movement of the second connector relative to the frame is permitted, and control means capable of driving the blocking means from the locking position to the unlocking position when the two connectors (62, 64) reach their relative closed test position and of driving the blocking means from their unlocking position to their locking position as soon as the two connectors (62, 64) leave their relative closed test position, said locking device comprising a lever pivoting on the frame with a control surface capable of cooperating with the first connector and a blocking surface capable of cooperating with an abutment on the second connector, and in particular the free end of the lever is configured as a cam surface or with a protuberance which can be pivotingly mobilized by a finger of the first connector to be separated from the abutment when the first and the second connectors (62, 64) are in closed position. - a frame that is fixed relative to the support; - a first and a second connector (62, 64) each comprising contacts of complementary forms, translationally mobile in a first direction relative to one another between an open position of disconnection between their contacts and a closed test position in which the contacts of the first connector are closed with the contacts of the second connector, the two connectors (62, 64) being translationally mobile in the first direction relative to the frame between a power disconnection position and a power connection position; - a positive locking device for the second connector comprising blocking means that are mobile between a locking position in which the second connector and the frame are locked in the power disconnection position and an unlocking position in which the relative movement of the second connector relative to the frame is permitted, and control means capable of driving the blocking means from the locking position to the unlocking position when the two connectors (62, 64) reach their relative closed test position and of driving the blocking means from their unlocking position to their locking position as soon as the two connectors (62, 64) leave their relative closed test position, said locking device comprising a lever pivoting on the frame with a control surface capable of cooperating with the first connector and a blocking surface capable of cooperating with an abutment on the second connector, and in particular the free end of the lever is configured as a cam surface or with a protuberance which can be pivotingly mobilized by a finger of the first connector to be separated from the abutment when the first and the second connectors (62, 64) are in closed position.