Abstract: A battery including two sets of terminals, in a battery replacement operation, a battery with a low charge mounted in a carrier is partially removed from the carrier while one set of terminals remain in electrical contact with contacts of the carrier. A fully charged battery is inserted into the carrier and electrically connected to the carrier with one of two sets of terminals prior to completely removing the battery with the low charge. During the battery replacement operation the carrier continues a normal operation.

Abstract: A locating recess for batteries is disposed at a portable power driven article and provides a size and shape corresponding the batteries. An open end is disposed at two opposite lateral sides thereof for the batteries being moved in and out. A power source terminal is provided for being able to electrically contact with an output end of at least one of the batteries.