a family of cordless electric tools and devices is adapted to use one or more identical rechargeable battery packs and each pack is adapted to interchangeably fit into a pocket or any one of a plurality of pockets in the tool or device in which the pack is employed . the battery pack is positively but releasably retained in the respective pocket of the tool or device with which it is used . a pair of standard ac prongs extend from a flat sidewall of the battery pack which is of a relatively flat , rectangular box - like shape . the prongs are adapted for insertion into a standard ac receptacle for charging the battery pack through rectifier means contained in the pack thus eliminating the need for a separate charger . when the battery pack is positioned in the respective pocket of the tool or device , a mechanical switch is actuated by mating formations on the pack and pocket and connects the battery pack in a discharge mode so that the particular tool or device can be powered from the pack battery through the same set of ac prongs . heavy duty tools or devices are provided with multiple pockets for the reception of a corresponding number of identical battery packs . cordless hedge and shrub trimmers , grass shears , sprayers , screwdrivers and lanterns exemplify tools and devices suited to the invention .