A charging system comprising a charging installation, a battery; and a charging control device connected to the charging installation, the charging control device including: a first electrode side supply path and a second electrode supply path which form a supply path from the charging installation to the battery; a first electrode side relay on the first electrode side supply path, a second electrode side relay on the second electrode side supply path, a controller configured to control opening and closing the first electrode side relay and the second electrode side relay; and a voltage measurement circuit configured to measure a voltage between the first electrode side supply path and the second electrode side supply path; wherein the first electrode side relay being located closer to the battery than the voltage measurement circuit; and the second electrode side relay being located closer to the battery than the voltage measurement circuit; characterized by a series circuit of a resistor and a resistance regulation relay; in that the controller is further configured to control opening and closing of the resistance regulation relay, and to control the resistance regulation relay to be closed when performing welding determination of the first electrode side relay and/or the second electrode side relay, and in that the charging installation is configured to switch off supplying power when performing welding determination of the first electrode side relay and/or the second electrode side relay, and the series circuit being connected in parallel to the voltage measurement circuit. a charging installation, a battery; and a charging control device connected to the charging installation, the charging control device including: a first electrode side supply path and a second electrode supply path which form a supply path from the charging installation to the battery; a first electrode side relay on the first electrode side supply path, a second electrode side relay on the second electrode side supply path, a controller configured to control opening and closing the first electrode side relay and the second electrode side relay; and a voltage measurement circuit configured to measure a voltage between the first electrode side supply path and the second electrode side supply path; wherein the first electrode side relay being located closer to the battery than the voltage measurement circuit; and the second electrode side relay being located closer to the battery than the voltage measurement circuit; characterized by a series circuit of a resistor and a resistance regulation relay; in that the controller is further configured to control opening and closing of the resistance regulation relay, and to control the resistance regulation relay to be closed when performing welding determination of the first electrode side relay and/or the second electrode side relay, and in that the charging installation is configured to switch off supplying power when performing welding determination of the first electrode side relay and/or the second electrode side relay, and the series circuit being connected in parallel to the voltage measurement circuit. a first electrode side supply path and a second electrode supply path which form a supply path from the charging installation to the battery; a first electrode side relay on the first electrode side supply path, a second electrode side relay on the second electrode side supply path, a controller configured to control opening and closing the first electrode side relay and the second electrode side relay; and a voltage measurement circuit configured to measure a voltage between the first electrode side supply path and the second electrode side supply path; wherein the first electrode side relay being located closer to the battery than the voltage measurement circuit; and the second electrode side relay being located closer to the battery than the voltage measurement circuit; characterized by a series circuit of a resistor and a resistance regulation relay; in that the controller is further configured to control opening and closing of the resistance regulation relay, and to control the resistance regulation relay to be closed when performing welding determination of the first electrode side relay and/or the second electrode side relay, and in that the charging installation is configured to switch off supplying power when performing welding determination of the first electrode side relay and/or the second electrode side relay, and the series circuit being connected in parallel to the voltage measurement circuit.