The last five years have produced dramatic improvements in understanding lead-acid batteries. Future battery technologies will build on these advances. Battery designs will incorporate more and thinner plates with grids produced from continuous processes using stronger, more corrosion-resistant grid alloys capable of longer life at elevated temperatures. Battery grids will become more sheet-like, producing more uniform discharges and higher utilization of active material. Batteries will be sealed and utilize gel, AGM, or novel separator/acid-retention systems which will apply uniform pressure to the active material for longer life. Improvements in charging systems will increase life and permit improved active-material utilization via rapid charging, partial state-of-charge operation, and reduction of overcharge. Possible advances are extremely thin film batteries to supply high power for vehicle starting or other applications. Advanced batteries for motive power will be rapidly recharged to provide three shift usage with charging between shifts. Robust lead-acid batteries for remote power locations will be continually operated in partial state-of-charge and charged with low currents. Purposely-built lead-acid batteries will drive hybrid or electric vehicles. Improved batteries for standby power applications will yield uniform cell-to-cell performance and longer life. This paper details the improvements in lead-acid battery technology that will permit these achievements to be realized.