Abstract: An example embodiment includes a hydraulic hybrid system. The hydraulic hybrid system includes a hydraulic system, an energy source configured to produce primary kinetic energy, an output configured to receive at least a first portion of the primary kinetic energy, and a transmission coupled between the energy source and the output and selectively coupled to the hydraulic system. The hydraulic system includes a reservoir, a sequenced accumulator assembly, and a hydraulic pump/motor that is hydraulically coupled to the reservoir and the sequenced accumulator assembly and configured to charge the sequenced accumulator assembly when mechanically driven. The sequenced accumulator assembly includes two or more accumulators, one or more sequence valves, and one or more check valves. The sequenced accumulator assembly is configured to store varying amounts of potential hydraulic energy by introducing and removing one or more of the accumulators from operation.