Battery charger for power hand tool

A battery charger for charging a battery of a power hand tool, the battery charger comprising:

• a housing having a charging chamber for receiving a battery under charging, a plurality of air vents for ventilation, and a communication hole in communication with the charging chamber;
• a charging circuit assembly mounted inside the housing and having a plurality of metal contacts exposed in the charging chamber for contacting the battery under charging in the charging chamber electrically;
• a fan mounted inside the housing and electrically connected to the charging circuit assembly and controllable by the charging circuit assembly to cause currents of air, the fan having a first ventilation side facing the air vents, and a second ventilation side opposite to the first ventilation side;
• a ventilation unit in air communication between the communication hole and the second ventilation side of the fan.