A power tool charging device configured to charge a battery pack for a power tool, comprising: a charging unit configured to supply direct current power to the battery pack for charging the battery pack of the power tool a condition detection unit configured to detect condition information of the battery pack when the battery pack is being charged; and an information processing unit configured to receive the condition information of the battery pack from the condition detection unit and configured to output the received condition information of the battery pack to a communication unit capable of performing near field communication with another device when the battery pack is being charged, further comprising a charging device body that accommodates the charging unit, the condition detection unit, and the information processing unit, wherein the charging device body includes: a plurality of terminals (26, 28) respectively connectable to a plurality of electrodes (32, 33) of the battery pack for attaching the battery pack to the charging device body in a removable manner, wherein the condition information includes the state of charge of the battery pack, characterized in that a slot of the charging device body is open to the exterior and configured to receive the communication unit in a removable manner, wherein the communication unit is card-type, wherein the slot is electrically connected to the information processing unit, wherein the condition information further includes a remaining charging time when the battery pack is being charged, wherein the information processing unit is configured to output the condition information of the battery pack when the slot receives the communication unit. a charging unit configured to supply direct current power to the battery pack for charging the battery pack of the power tool a condition detection unit configured to detect condition information of the battery pack when the battery pack is being charged; and an information processing unit configured to receive the condition information of the battery pack from the condition detection unit and configured to output the received condition information of the battery pack to a communication unit capable of performing near field communication with another device when the battery pack is being charged, further comprising a charging device body that accommodates the charging unit, the condition detection unit, and the information processing unit, wherein the charging device body includes: a plurality of terminals (26, 28) respectively connectable to a plurality of electrodes (32, 33) of the battery pack for attaching the battery pack to the charging device body in a removable manner, wherein the condition information includes the state of charge of the battery pack, a plurality of terminals (26, 28) respectively connectable to a plurality of electrodes (32, 33) of the battery pack for attaching the battery pack to the charging device body in a removable manner, wherein the condition information includes the state of charge of the battery pack, characterized in that a slot of the charging device body is open to the exterior and configured to receive the communication unit in a removable manner, wherein the communication unit is card-type, wherein the slot is electrically connected to the information processing unit, wherein the condition information further includes a remaining charging time when the battery pack is being charged, wherein the information processing unit is configured to output the condition information of the battery pack when the slot receives the communication unit.