  In this paper we present some features of Q-balls and we discuss their
interactions with matter, and their energy losses in the Earth, for a large
range of velocities. These calculations are used to compute the fractional
geometrical acceptance of the MACRO detector. Furthermore a systematic analysis
of the energy losses of Q-balls in three types of detectors is investigated.
More specifically we have computed the light yield in liquid scintillators, the
ionization in streamer tubes and the Restricted Energy Loss in the CR39 nuclear
track detectors.
