  In a previous paper, we have studied multi-brane solutions in the context of
cubic superstring field theory. The kinetic term of the action was computed for
these multi-brane solutions, and for the evaluation of the energy, the equation
of motion contracted with the solutions itself was simply assumed to be
satisfied. In this paper, we compute the cubic term of the action and discuss
the validity of the previous assumption. Additionally, we evaluate the
Ellwood's gauge invariant observable.
