A kit comprising a plurality of power tools configured to operate at different voltages, a plurality of receivers configured to provide different output charging voltages and means for selectively engaging each receiver with only one or more power tools having an operating voltage equal to or greater than the output charging voltage of the receiver to charge the one or more power tool. The selective engagement means being in the form of a plurality of terminal block. Each terminal block may be secured to a respective one of the power tools. Each terminal block may include a rib and each receiver may define a slot to receivingly engage one of the ribs. The rib of each terminal block may be disposed at a different location than the ribs of the other terminal blocks, and the slot of each receiver may be positioned at a different location than the slots of the other receivers. Some of the receivers may engage more than one of the terminal blocks so that the receivers may engage the power tools that operate at the same or greater voltages than the charging voltage of the receivers.