A circuit comprising a contactor assembly for a battery module of an electric work vehicle and a battery management system, wherein in use, the battery module is configured to be charged and discharged via the circuit and wherein: the circuit comprises the contactor assembly, the contactor assembly comprising a first contactor and a second contactor, wherein the first contactor is in series with the second contactor; and characterised in that: each of the first contactor and the second contactor is configured to have a higher resistance to welding for a switching current flowing in a preferred direction than in a nonpreferred direction; the first contactor is configured to have a preferred direction in a first direction and a nonpreferred direction in a second direction; and the second contactor is configured to have a preferred direction in the second direction and a nonpreferred direction in the first direction; in response to an instruction to switch the contactor assembly, the battery management system is configured to: determine whether the switching current direction is in the first direction or in the second direction; in an event that the instruction to switch comprises an instruction to open the contactor assembly: first, open the contactor having a preferred direction in the switching current direction; and subsequently, open the contactor having a nonpreferred direction in the switching current direction; in an event that the instruction to switch comprises an instruction to close the series contactor assembly: first, close the contactor having a nonpreferred direction in the switching current direction; and subsequently, close the contactor having a preferred direction in the switching current direction. each of the first contactor and the second contactor is configured to have a higher resistance to welding for a switching current flowing in a preferred direction than in a nonpreferred direction; the first contactor is configured to have a preferred direction in a first direction and a nonpreferred direction in a second direction; and the second contactor is configured to have a preferred direction in the second direction and a nonpreferred direction in the first direction; in response to an instruction to switch the contactor assembly, the battery management system is configured to: determine whether the switching current direction is in the first direction or in the second direction; in an event that the instruction to switch comprises an instruction to open the contactor assembly: first, open the contactor having a preferred direction in the switching current direction; and subsequently, open the contactor having a nonpreferred direction in the switching current direction; in an event that the instruction to switch comprises an instruction to close the series contactor assembly: first, close the contactor having a nonpreferred direction in the switching current direction; and subsequently, close the contactor having a preferred direction in the switching current direction. determine whether the switching current direction is in the first direction or in the second direction; in an event that the instruction to switch comprises an instruction to open the contactor assembly: first, open the contactor having a preferred direction in the switching current direction; and subsequently, open the contactor having a nonpreferred direction in the switching current direction; first, open the contactor having a preferred direction in the switching current direction; and subsequently, open the contactor having a nonpreferred direction in the switching current direction; in an event that the instruction to switch comprises an instruction to close the series contactor assembly: first, close the contactor having a nonpreferred direction in the switching current direction; and subsequently, close the contactor having a preferred direction in the switching current direction. first, close the contactor having a nonpreferred direction in the switching current direction; and subsequently, close the contactor having a preferred direction in the switching current direction.