  We investigate the collision dynamics of $U(1)$ gauged Q-balls by performing
high-resolution numerical simulations in axisymmetry. Focusing on the case of
relativistic head-on collisions, we consider the effects of the initial
velocity, relative phase, relative charge, and electromagnetic coupling
strength on the outcome of the collision. We find that the collision dynamics
can depend strongly on these parameters; most notably, electromagnetic effects
can significantly alter the outcome of the collision when the gauge coupling is
large. When the gauge coupling is small, we find that the dynamics generally
resemble those of ordinary (non-gauged) Q-balls.
