A clamp for a male terminal of a power source, the terminal including a frustoconical body projecting out of a base surface that is part of the source against which a greatest diameter of the terminal rests, may include: at least one ring-shaped first portion, with an open section of its circumference, the at least one first portion having a first diameter such that a predetermined radial clearance exists when the at least one first portion axially fits upon the frustoconical body, the at least one first portion also having two jaws which axially project out of the circumference of the at least one first portion, the jaws being in opposed, spaced-apart relationship; and a clamping device which acts on the jaws and is configured to move the first jaws toward each other to tighten the at least one first portion around the frustoconical body with elimination of the clearance.