An on-board electrical system for an electric vehicle comprising: a high-voltage electrical power supply (15) including a high-voltage electrical storage system (5) connected in series with a high-voltage switch (16), a first low-voltage power supply (18) including a first low-voltage electrical storage system (6) connected in series with a first electrical switch (19), second low-voltage power supply (20) including a second low-voltage electrical storage system (7) connected in series with a second electrical switch (21), a first DC/DC converter (9) connected to the high-voltage electrical power supply (15) and to the first low-voltage power supply (18) via a first low-voltage DC bus (22), a second DC/DC converter (10) connected to the high-voltage electrical power supply (15) and to the second low-voltage power supply (20) via a second low-voltage DC bus (23), a first master electronic control unit (ECU1) connected to the first low-voltage DC bus (22) for power supply and configured to controlling operation of the first electrical switch (19), a second master electronic control unit (ECU2) connected to the second low-voltage DC bus (23) for power supply and configured to controlling operation of the second electrical switch (21), a first wake-up electrical connector arrangement (29) suitable for being temporarily connected a low-voltage jump-starter device (31), a first wake-up electrical line (32) connecting the first wake-up electrical connection arrangement (29) with the first low-voltage DC bus (22), a second wake-up electrical line (33) connecting the first wake-up electrical connector arrangement (29) with the second low-voltage DC bus (23).