Abstract: System and method for a portable propane-fueled battery charger. One system includes a battery charger including a propane fuel line and an engine including an output shaft. The engine is configured to receive propane via the propane fuel line and rotationally drive the output shaft. The battery charger further includes an alternator including a rotor and stator coils. The output shaft is mechanically coupled to the rotor, and the rotor is rotationally driven by the output shaft. An electrical current is induced in the stator coils by rotation of the rotor. The battery charger further includes an electrical circuit that receives the electrical current and is configured to determine when a battery pack is coupled to a battery connector, and charge the battery pack.

Abstract: A wrench is configured to rotate a fastener and including a handle, and a head coupled to the handle. The head includes a first jaw configured to engage the fastener and a second jaw configured to engage the fastener. The second jaw includes a rack gear and the second jaw is movable with respect to the first jaw to adjust a distance between the first jaw and the second jaw. The wrench also includes an adjustment mechanism operable to move the second jaw with respect to the first jaw. The adjustment mechanism includes a worm gear that engages the rack gear. The rack gear includes a plurality of teeth defining a rectangular profile between each of the plurality of teeth.