This paper presents a novel approach for UAV battery management of the energy-aware mapping mission planning. The optimization strategy aims to reduce overall flight time by considering necessary battery replacements. Energy constraints are imposed as the capacities of available batteries are limited. The resulting mission plan reduces the unnecessary long flight distances from and to the base station. This strategy also considers the choice of the base location. Potential base locations are fixed and placed at the vertices of the mapping area for easy access. Iterative optimization results in choosing the location with the minimal total mission flight distance. The optimal solution of the proposed approach is compared to its initial solution, where the mapping area is decomposed proportionally to the capacities of batteries planned to be used in the mission. Simulation results for the realistic test case mapping area of the vineyard and olive orchard show that fewer battery replacements are needed and both total flight time and total flight distance are reduced when implementing the proposed optimization strategy. Moreover, mission safety is increased as the number of take-offs and landings, which pose high risk, are reduced.