A capacitor module for a vehicle, wherein the module comprises - a capacitor comprising a plurality of capacitor cells operatively connected to each other, - a first port configured to be connected to a power supply arrangement, - a second port configured to be connected to an electric machine for cranking an internal combustion engine and - a third port configured to be connected to ground, wherein the capacitor module comprises a first electrical device connected between the first port and the capacitor, characterized in that the first electrical device is adapted for allowing a current to flow out from the capacitor module via the first port for providing power to at least one load during operation in case of a sudden voltage drop in the power supply from the power supply arrangement resulting from a current transient, wherein the first electrical device comprises a diode arranged for providing a low resistance against the current in one direction and a high resistance in the other direction, wherein the capacitor module comprises a second electrical device connected between the first port and the capacitor and wherein the second electrical device is adapted for opening and closing, respectively, an electrical connection between the first port and the capacitor in response to a control signal, wherein the second electrical device is connected in series with the first electrical device, and wherein the second electrical device comprises two metal-oxide-semiconductor field-effect transistors arranged in a back-to-back relationship. - a capacitor comprising a plurality of capacitor cells operatively connected to each other, - a first port configured to be connected to a power supply arrangement, - a second port configured to be connected to an electric machine for cranking an internal combustion engine and - a third port configured to be connected to ground, wherein the capacitor module comprises a first electrical device connected between the first port and the capacitor, characterized in that the first electrical device is adapted for allowing a current to flow out from the capacitor module via the first port for providing power to at least one load during operation in case of a sudden voltage drop in the power supply from the power supply arrangement resulting from a current transient, wherein the first electrical device comprises a diode arranged for providing a low resistance against the current in one direction and a high resistance in the other direction, wherein the capacitor module comprises a second electrical device connected between the first port and the capacitor and wherein the second electrical device is adapted for opening and closing, respectively, an electrical connection between the first port and the capacitor in response to a control signal, wherein the second electrical device is connected in series with the first electrical device, and wherein the second electrical device comprises two metal-oxide-semiconductor field-effect transistors arranged in a back-to-back relationship. wherein the capacitor module comprises a first electrical device connected between the first port and the capacitor, characterized in that the first electrical device is adapted for allowing a current to flow out from the capacitor module via the first port for providing power to at least one load during operation in case of a sudden voltage drop in the power supply from the power supply arrangement resulting from a current transient, wherein the first electrical device comprises a diode arranged for providing a low resistance against the current in one direction and a high resistance in the other direction, wherein the capacitor module comprises a second electrical device connected between the first port and the capacitor and wherein the second electrical device is adapted for opening and closing, respectively, an electrical connection between the first port and the capacitor in response to a control signal, wherein the second electrical device is connected in series with the first electrical device, and wherein the second electrical device comprises two metal-oxide-semiconductor field-effect transistors arranged in a back-to-back relationship.