Stark didn't reapply the dampeners until the next day, when he actually ran out of energy(for only a few minutes). Onslaught also broke free of everything right when that happened, so Quentin was never solo fighting it.
That night his suit still had juice, and he never reapplied the dampener until he ran out of the energy the next day(when Onslaught broke free). This could only mean it was active the entire time.