The previously developed control methods based on the conservation of energy in circuits require the accurate estimation of energy losses, which is difficult to measure and calculate for boost converters. Consequently, there always exist steady-state errors in the output voltage if neglecting such circuit energy losses. To address this issue, an improved energy balance control (IEBC) method is proposed in this paper by integrating a simplified energy balance controller (SEBC) with a PI controller. The proposed IEBC can reduce the steady-state output voltage errors without requiring the estimation of circuit energy losses. Furthermore, the proposed IEBC can operate in both the continuous current mode (CCM) and the discontinuous current mode (DCM), thus accurate static and fast dynamic performances are achieved over the entire load operation range. Moreover, the stability of the IEBC is proved using the Lyapunov stability criterion. Compared with that of the SEBC, both simulations and experiments validate the feasibility and robustness of the proposed IEBC method.