The present invention provides regenerative passive and semi-active suspension systems. A regenerative suspension system generally includes at least one regenerative damper, a module, an electric switch, and a battery. The at least one regenerative damper converts mechanical vibration energy within a vehicle into a voltage, which the damper passes to the module. The module measures the voltage from the regenerative damper, and in response, changes electric switch settings for each regenerative damper between an open circuit, a closed circuit completed by a power resistance, and a closed circuit completed by circuitry for charging a battery. Additionally, the module sets electric switch levels to adjust the damping forces within each regenerative damper.