Battery pack and cordless power tool having the same

A cordless power tool comprising:

• a main housing having an internal housing space;
• a handle portion extending from the main housing and having an internal handle space in communication with the housing space, the handle having a free end portion;
• a DC motor disposed in the housing space;
• a fan disposed in the housing space and rotatable by the DC motor;
• and
• a battery pack comprising:
• an accommodation portion for accommodating therein at least one battery cell and formed with a vent hole for fluid communication between an atmosphere and an internal space of the accommodation portion;
• an insertion portion extending from the accommodation portion and attachable to the free end portion of the handle portion, the insertion portion being in fluid communication with the accommodation portion and formed with a vent hole for fluid communication between the insertion portion and the handle space to define an air passage in an inside of the battery pack;
• and
• a switching element connected between the at least one rechargeable battery cell and the DC motor and positioned at the air passage.

A battery pack accommodating therein a plurality of battery cells and to be assembled into a power tool provided with a portion having an internal space, the battery pack comprising:

• an insertion portion insertable into the internal space;
• an accommodation portion connected to the insertion portion and disposed outside of the power tool when the insertion portion is inserted into the internal space, all battery cells being accommodatable into the accommodation portion;
• and
• a protection board having a protection circuit, at least a part of the protection board being located in the insertion portion.