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.

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.

Abstract: A battery tester engages a power tool battery and includes a housing having a cavity for receiving a stem of the power tool battery. The battery tester has a plurality of electrically conductive contacts disposed in the cavity and is configured to engage corresponding battery electrodes on the stem. A processor is mounted within the housing and communicates with the battery through the electrically conductive contacts. The processor measures a voltage level of the battery, and a loading circuit electrically loads the battery during measuring. One or more indicators are controlled by the processor. The processor activates the loading circuit for a predetermined period of time to measure a voltage level of the battery while under load, and then activates the indicators to provide a visual indication of remaining battery life. The battery tester is a stand-alone device where housing does not have a motor or a battery charger.

Abstract: A battery pack that is capable of supplying high- and low-current discharge to end products. The battery pack includes a cylindrical housing with a lithium-ion battery cell enclosed within the housing. The housing also includes a first end portion, a second end portion, and a body portion. The first end portion includes a plurality of terminals for electrically connecting to the end product. The terminals include a high-current discharge terminal, a low-current discharge terminal, a battery pack identification terminal, a battery pack temperature terminal, and a positive voltage terminal. The second end portion includes a recess for removably securing the battery pack to an end product, such as a battery charger or a power tool. Included within the battery pack housing is circuitry for controlling the charging and discharging of the battery pack through the low-current discharge terminal.

Abstract: A battery tester engages a power tool battery and includes a housing having a cavity for receiving a stem of the power tool battery. The battery tester has a plurality of electrically conductive contacts disposed in the cavity and is configured to engage corresponding battery electrodes on the stem. A processor is mounted within the housing and communicates with the battery through the electrically conductive contacts. The processor measures a voltage level of the battery, and a loading circuit electrically loads the battery during measuring. One or more indicators are controlled by the processor. The processor activates the loading circuit for a predetermined period of time to measure a voltage level of the battery while under load, and then activates the indicators to provide a visual indication of remaining battery life. The battery tester is a stand-alone device where housing does not have a motor or a battery charger.