A battery life extender (12) for a portable lighting device (10) employs a reconfigurable mechanism operable to selectively electrically isolate one or more batteries (20) from a circuit having a parasitic power drain. For example, a lighting device (10) includes a light generating element (14), at least one battery (20), a user operated switch (16) configured to control delivery of electrical power from the at least one battery (20) to the light generating element (14), and a housing assembly (18) supporting the at least one battery (20) and the light generating element (14). The user operated switch (16) can impart a parasitic power drain. The housing assembly (18) is reconfigurable to: (a) a first configuration in which the user operated switch (16) is electrically connected to the at least one battery (20), and (b) a second configuration in which the at least one battery (20) is electrically isolated and the at least one battery (20) is retained by the housing assembly (18).