The rapid deterioration of dynamic charge acceptance (DCA) of all varieties of lead-acid batteries severely limits micro-hybrid vehicle performance. This weakness is a result of early and rapid negative plate sulfation which profoundly decreases DCA, thus increasing charge time. As a result, the possible engine-off time required for improved fuel efficiency and emissions reduction is limited. Automotive manufacturers are planning to increase the engine-off time for next-generation micro-hybrid vehicles (Micro-II hybrids) by shutting down the engine during low speed decelerations. This advancement will necessitate batteries with higher DCA and greater stop-start cycle life. These requirements cannot be met by conventional or advanced lead-acid batteries. Simulation testing shows that the Axion PbC® battery can meet the present and future demands of micro-hybrid vehicles with a low-cost, high efficiency two-battery solution that maintains high DCA (i.e., low charge time) for over 100,000 stop-start events (eight years of equivalent vehicle operation).