In micro hybrid vehicles, the lead-acid battery is a crucial component for improved fuel economy by using stop/start function of the engine and regenerative braking. The lead-acid battery has a limited dynamic charge acceptance (DCA) and therefore, it can use only a small part of more than 150 A (provided by the alternator during regenerative braking) which reduces fuel efficiency. Therefore, it is important to establish test methods and a mechanistic model for DCA under realistic vehicle usage conditions. Within this work, the causes of the limited DCA are analysed. From the findings, a model for describing DCA and an accelerated measurement method to derive DCA as it is under real world conditions were developed. The proposed test method is now published as EN standard (EN 50342-6). This is the first time that a validated measurement method for DCA for is established, that even ca be performed in a relatively short time. The electrochemical reasons for the limited DCA were analysed by applying post-mortem-analysis on the morphology of the active masses and by electrical tests on cells and single electrodes. The focus of this work was on enhanced flooded batteries (EFB), which satisfy the durability requirements of many micro hybrid vehicles at significantly lower cost than AGM batteries, but present some additional complexity for the measurement and understanding of DCA.