Today lead acid batteries are the most commonly used energy storage technology in material handling systems. Evaluation methods for the energy efficiency of forklifts, traction batteries and chargers have gained in relevance in this field. Generally, representative cycles are used to determine the energy efficiency in order to avoid multiple long lasting cycle live tests. At first glance this seems to be the adequate approach. However, for electrochemical storage systems with significant side reactions - like lead acid batteries - this procedure leads, to significantly lower values for energy efficiencies than in real life applications. While these battery systems need some overcharging to reach fully charged state, an overcharge is not necessary at every charge/discharge cycle. We report on results obtained with flooded lead acid batteries demonstrating that with a management strategy which includes operation in a partial state of charge, energy efficiencies of about 0.87 can be reached with minimal impact on lifetime. The usage of a typical representative cycle leads to an efficiency value of 0.77 with active electrolyte circulation respectively 0.70 without. We were able to identify the so called ’hard sulfation’ of the negative plates as the major failure mode of insufficiently charged batteries.