A POWER SUPPLY CIRCUIT AND A METHOD FOR CONTROLLING A POWER SUPPLY CIRCUIT

The present application relates to a power supply circuit of a vehicle, which power supply circuit comprises a first side (A) comprising a power source (14), a first battery pack (12) and first power consumers (16), a second side (B) connected in series with the first side (A), the second side (B) comprising a second battery pack (18) and second power consumers (20), an overload current breaker (22) provided between the first and the second side, said overload current breaker (22) having a pre- determined threshold breaking current (IThreshold) value, at which value the circuit is broken; a controller (24) connected to said power source for regulating voltage from said power source (14), the controller (24) being provided with said threshold breaking current (IThreshold) value, the controller further being operatively connected to devices (26, 28) providing information related to a current (Ich) through said overload current breaker (22). The controller (24) is arranged to determine a maximum permissible charging current (IPermissible) value in relation to the threshold breaking current (IThreshold) value; to set a low voltage (V) from said power source (14) for charging said second battery pack (18) at activation of said power source (14); to monitor, with the information from the devices (26, 28), the charging current (Ich) through said overload current breaker (22) to the second battery pack (18) and to compare the charging current (Ich) with the maximum permissible charging current (IPermissible); to increase the voltage (V) of the power source (14) if the charging current (Ich) is below the maximum permissible charging current (Ich < IPermissible); and to decrease the voltage (V) of the power source (14) if the charging current (Ich) is the same as or above the maximum permissible current (Ich ≥ IPermissible).