depiction of connections from contacts 201 203 to external circuitry has been omitted for clarity but should be obvious to those skilled in the art fig3 a depicts a first state in which dry cell 301 has been positioned so that its anode 302 has just begun to touch coil 105 of spring 101 spring 101 39 s coils 102 108 are therefore only slightly compressed none sufficiently to be advanced into contacts 202 or 203 in this first state spring 101 is in electrical and mechanical contact with contact 201 this creates a first circuit connecting battery anode 302 with contact 201 via spring 101 in this first state contacts 202 and 203 are open circuits fig3 b depicts a second state in which dry cell 301 is applying an additional compressing force to spring 101 as would happen for example if the entire switch assembly comprising 101 108 and 201 205 were squeezed partially together with dry cell 301 said compression of spring 101 forces coils 103 and 107 into contact with contact 202 creating a second circuit said second circuit electrically connects battery anode 302 with contacts 201 202 via spring 101 fig3 c depicts a third condition in which dry cell 301 has advanced.