  Collisions of non-topological solitons, Q-balls, are studied in the Minimal
Supersymmetric Standard Model in two different cases: where supersymmetry has
been broken by a gravitationally coupled hidden sector and by a gauge mediated
mechanism at a lower energy scale. Q-ball collisions are studied numerically on
a two dimensional lattice for a range of Q-ball charges. Total cross-sections
as well as cross-sections for fusion and charge exchange are calculated.
