Abstract: A method of estimating a state-of-charge of a battery pack having one or more cells is provided. The method includes obtaining, by a battery controller of the battery pack, data from a device electrically coupled to the battery pack. The data is indicative of a power requirement for the device. The method can further include determining, by the battery controller, a state-of-charge of the battery pack based, at least in part, on the data indicative of the power requirement for the device.

Abstract: A battery pack that includes a housing connectable to and supportable by a tool. The battery pack also includes a controller having a processor and a memory. The controller is connected to one or more sensors which provide data to the controller related to operational characteristics of the battery pack. The controller stores the operational characteristics of the battery pack in the memory. The battery pack also includes a battery pack black box. The controller communicates with the black box using a wired communication bus and transmits the stored operational characteristics of the battery pack to the black box. The battery pack black box is capable of transmitting the stored operational characteristics wirelessly to a device external to the battery pack.

Abstract: A device that includes a controller having a processing unit and a memory. The device includes an enable circuit. The enable circuit prevents the device from operating (e.g., discharging current and/or receiving charging current) until the enable circuit is activated. The enable circuit includes an activation component (e.g., a near-field communication [“NFC”] circuit). The activation component is configured or operable to cause the device to become enabled when the activation component is activated by an external enabling device.

Abstract: A power tool including a motor, a first battery pack, a second battery pack, a first switching element coupled between the first battery pack and the motor, a second switching element coupled between the second battery pack and the motor, and controller coupled to the first switching element and the second switching element. The controller includes a first pulse-width modulation (PWM) output coupled to the first switching element and a first PWM signal to selectively close the first switching element. The controller further includes a second PWM output coupled to the second switching element and a second PWM signal to selectively close the second switching element.