Both of these systems leave the existing HSD system mostly unchanged and could be similarly applied to other hybrid powertrain flavors by simply replacing the stock NiMH batteries with a higher capacity battery pack and a charger to refill them for about $0.03 per mile from standard household outlets. See also Comparison of Toyota hybrids Mild hybrid Hybrid car Inverter (electrical) Insulated Gate Bipolar Transistor Variable-frequency drive Global Hybrid Cooperation Integrated Motor Assist List of hybrid vehicles References External links Hybrid Synergy Drive movie from Toyota Evaluation of the 2010 Toyota Prius Hybrid Synergy Drive System Animation showing how HSD works Power Split Device Animation showing MG1 and the MG2 Toyota Hybrid powertrain Automotive technology tradenames Continuously variable transmissions Automotive transmission technologies Engine technology