Using initial conditions
To find what Qo is, we look at initial conditions:
Q(t=0) = CVB + Qo = 0 (capacitor is initially uncharged). Therefore we have: Qo = -CVB
Q(t) = CVB (1 - e-t/RC) .
For t very big, this says: Q(t=large) = CVB, or that the capacitor will be fully charged!