Patent ID: 8684106

Claim:
A battery pack comprising: a housing including an upper housing portion having an opening and longitudinally extending side walls and a lower housing portion having a lower surface, longitudinally extending side walls and transversely extending end walls, said upper housing portion and said lower housing portion engageable with each other; a plurality of lithium-ion battery cells disposed in said lower housing portion, said plurality of lithium-ion battery cells being arranged in parallel with said lower surface; a circuit board disposed above said plurality of lithium-ion battery cells in said lower housing portion and electrically connected to said plurality of lithium-ion battery cells; a plurality of terminals including a positive terminal, a negative terminal and a signal communicating terminal, said plurality of terminals being arranged in a direction transverse to the longitudinal direction of said side walls, and each terminal of said plurality of terminals including an engaging portion adjacent to said opening when said upper housing and said lower housing portions are engaged, and a connecting portion connected to said circuit board; and a protecting portion positioned between said engaging portion and said connecting portion to protect against foreign matter from contacting said circuit board through said opening, wherein the upper housing portion is configured to directly connect to a housing of an electric tool, and the lower housing portion is configured not to directly connect to the housing of the electric tool.