Abstract: A battery pack for an electrical device including a housing having a first housing portion defining a first compartment and a second housing portion defining a second compartment, a plurality of battery cells disposed within the first compartment and configured to supply power to the electrical device, a circuit board disposed within the first compartment and including a heat generating component, and a heat sink coupled to the second housing portion and disposed adjacent the heat generating component. The heat sink includes a first portion extending toward the heat generating component and disposed within the first compartment, and a second portion extending away from the heat generating component and disposed within the second compartment.

Abstract: Electric tool system and method of operating the same. One electric tool system includes a first electric tool and a second electric tool. A method of operating the electric tool system includes providing a first battery for the first electric tool and a second battery for the second electric tool. The method further includes designating the first battery as a master, and designating the second battery as a slave. The method further includes configuring the first electric tool to a first operating mode, detecting a first operating parameter by the master, and transmitting a first signal from the master to the slave based on the first operating parameter detected by the master. The method further includes the slave receiving the first signal from the master and enabling operation of the second electric tool.