An electrical system for delivering power from a first energy source to a second energy source, the electrical system comprising: a first interface (106, 306) configured to be coupled to the first energy source; a second interface (114, 314) configured to be coupled to the second energy source; a double pole double throw, DPDT, latching relay (108, 308) coupled between the first energy source and the second interface; and a processing system (122, 322) coupled to the DPDT latching relay (108, 308) and the second interface, wherein the processing system (122, 322) is configured to: identify a connection event based on an electrical characteristic of the second interface (114, 314) that is indicative of the second interface (114, 314) being coupled to the second energy source; and in response to identifying the connection event, operate the DPDT latching relay (108, 308) in a first switching state to provide a path for current from the first energy source; and an internal energy source (124, 324), wherein the internal energy source (124, 324) is coupled to power the processing system (122, 322) via the DPDT latching relay (108, 308) in a second switch state when the switching element (108, 308) is operated to remove the path for current from the first energy source, wherein the DPDT latching relay (108, 308) has a first terminal coupled to the internal power source (124, 324) and a second terminal coupled to the processing system (122, 322), a third terminal coupled to circuitry that comprises a power conversion module and a battery management circuitry and receives power via the DPDT latching relay (108, 308) from the first energy source for charging the internal energy source (124, 324) when the switching element (108, 308) is operated in the first switching state, a fourth terminal coupled to the first interface (106, 306), a fifth terminal coupled to the power conversion module, and a sixth terminal, wherein in the first switching state of the switching element (108, 308), the third terminal is connected to the first terminal and the fourth terminal is connected to the fifth terminal, wherein in the second switching state of the switching element (108, 308), the second terminal is connected to the first terminal and the fifth terminal is connected to the sixth terminal. a first interface (106, 306) configured to be coupled to the first energy source; a second interface (114, 314) configured to be coupled to the second energy source; a double pole double throw, DPDT, latching relay (108, 308) coupled between the first energy source and the second interface; and a processing system (122, 322) coupled to the DPDT latching relay (108, 308) and the second interface, wherein the processing system (122, 322) is configured to: identify a connection event based on an electrical characteristic of the second interface (114, 314) that is indicative of the second interface (114, 314) being coupled to the second energy source; and in response to identifying the connection event, operate the DPDT latching relay (108, 308) in a first switching state to provide a path for current from the first energy source; and identify a connection event based on an electrical characteristic of the second interface (114, 314) that is indicative of the second interface (114, 314) being coupled to the second energy source; and in response to identifying the connection event, operate the DPDT latching relay (108, 308) in a first switching state to provide a path for current from the first energy source; and an internal energy source (124, 324), wherein the internal energy source (124, 324) is coupled to power the processing system (122, 322) via the DPDT latching relay (108, 308) in a second switch state when the switching element (108, 308) is operated to remove the path for current from the first energy source, wherein the DPDT latching relay (108, 308) has a first terminal coupled to the internal power source (124, 324) and a second terminal coupled to the processing system (122, 322), a third terminal coupled to circuitry that comprises a power conversion module and a battery management circuitry and receives power via the DPDT latching relay (108, 308) from the first energy source for charging the internal energy source (124, 324) when the switching element (108, 308) is operated in the first switching state, a fourth terminal coupled to the first interface (106, 306), a fifth terminal coupled to the power conversion module, and a sixth terminal, wherein in the first switching state of the switching element (108, 308), the third terminal is connected to the first terminal and the fourth terminal is connected to the fifth terminal, wherein in the second switching state of the switching element (108, 308), the second terminal is connected to the first terminal and the fifth terminal is connected to the sixth terminal.