Abstract: Power supply systems for a power tool and power tool systems are provided. A power supply system for a power tool includes a first battery control circuit operable to interface one or more first batteries, the first battery control circuit having a first positive terminal and a first negative terminal. The power supply system further includes a second battery control circuit operable to interface one or more second batteries, the second battery control circuit having a second positive terminal and a second negative terminal. The power supply system further includes a first diode electrically coupled between the first positive terminal and the second negative terminal. The power supply system further includes a second diode electrically coupled between the first negative terminal and the second positive terminal.

Abstract: Power packs configured to supply power to a common load are provided. A power pack includes a first power source; a second power source; at least one adapter configured to receive the common load and electrically couple the common load to at least one of the first power source or the second power source for supplying power to the common load; a tether interface electrically coupled to the at least one adapter, the first power source, and the second power source and configured to arrange the first power source and the second power source in series or in parallel; and a control circuit comprising at least one controller for performing a plurality of operations.

Abstract: A battery pack assembly configured to supply power to a common load includes a backpack wearable on a back of a user, at least one battery arranged in the backpack and electrically coupled to the common load via a tether, and a communications interface operable between the battery pack and the common load. The communications interface is configured to perform one or more operations, including but not limited to receiving and transmitting operational information to and from the battery pack and the common load, the operational information relating to at least one of the battery pack or the common load.

Abstract: An apparatus for producing a water feature in a spa/pool/hot-tub (“spa”) is disclosed. The apparatus includes a flume developer having internal dimensions that generate a water pressure from a water flow received from a water source associated with the spa. The flume developer further includes a head assembly having one or more apertures through which the water feature is produced based on the water pressure. The flume developer further includes a flange configured to abut against an outer surface of the spa. The flume developer is interchangeable in a water feature device body connected to the water source. A light source can be provided to illuminate the water feature.