<p>Since the slow convergent speed and poor robustness of the asymptotic control strategy in balancing the state-of-charge (SOC) of battery energy storage units (BESUs), two distributed practical finite time control laws are used in this paper to solve the problem of quickly balancing the SOC of all BESUs in a battery energy storage system (BESS) while meeting the total charge and discharge power requirements. Firstly, the communication topology between the BESUs is established. Then, a finite-time control law and a practical fixed-time control law are designed for each battery energy storage unit. Secondly, through the theory of finite time stability and a time base generator, it is proved that the state error between BESUs and the power tracking error of the BESS under the two control laws converge to arbitrarily adjustable neighborhoods of the origin in finite time. In addition, the convergence time of the practical fixed-time control law does not depend on the initial states and can be pre-designated. Compared with the existing asymptotic control methods, the proposed methods have a faster convergence speed and a smaller SOC balancing error though numerical simulations.</p>