A discharge system for an electric vehicle that has two voltage domains, wherein a higher of the voltage domains is for providing power for driving an electric motor of the electric vehicle and a lower of the voltage domains is for providing power for components of the electric vehicle, the discharge system comprising: a user interaction input component configured to receive input that originated from a human user, wherein the input indicates that the electric vehicle is to shutdown; a step-down power converter configured to step down an input voltage in the higher voltage domain to an output voltage in the lower voltage domain, wherein the input voltage is higher than the output voltage, wherein the step-down power converter is a backup or emergency power converter that is coupled to output the output voltage across supply rails (155, 160) in the lower voltage domain and supply the user interaction component with power in the lower voltage domain in an event of a failure of a battery in the lower voltage domain to supply the user interaction component with power; discharge circuitry coupled to the output of the step-down power converter between the supply rails (155, 160) in the lower voltage domain, wherein the discharge circuitry is reversibly driveable to load the step-down power converter; the battery coupled across the supply rails (155, 160) in the lower voltage domain; and discharge drive circuitry configured to drive the discharge circuitry to load the step-down power converter in response to the input received by the user interaction input component indicating that the electric vehicle is to shutdown, wherein the discharge drive circuitry comprises electronics coupled to be supplied with power from the supply rails (155, 160) in the low voltage domain, wherein the electronics include an output terminal coupled to provide a discharge drive signal to the discharge circuitry, wherein the discharge circuitry is reversibly driveable by the discharge drive signal to allow current to flow between the supply rails in the lower voltage domain. a user interaction input component configured to receive input that originated from a human user, wherein the input indicates that the electric vehicle is to shutdown; a step-down power converter configured to step down an input voltage in the higher voltage domain to an output voltage in the lower voltage domain, wherein the input voltage is higher than the output voltage, wherein the step-down power converter is a backup or emergency power converter that is coupled to output the output voltage across supply rails (155, 160) in the lower voltage domain and supply the user interaction component with power in the lower voltage domain in an event of a failure of a battery in the lower voltage domain to supply the user interaction component with power; discharge circuitry coupled to the output of the step-down power converter between the supply rails (155, 160) in the lower voltage domain, wherein the discharge circuitry is reversibly driveable to load the step-down power converter; the battery coupled across the supply rails (155, 160) in the lower voltage domain; and discharge drive circuitry configured to drive the discharge circuitry to load the step-down power converter in response to the input received by the user interaction input component indicating that the electric vehicle is to shutdown, wherein the discharge drive circuitry comprises electronics coupled to be supplied with power from the supply rails (155, 160) in the low voltage domain, wherein the electronics include an output terminal coupled to provide a discharge drive signal to the discharge circuitry, wherein the discharge circuitry is reversibly driveable by the discharge drive signal to allow current to flow between the supply rails in the lower voltage domain.