Electrically heated smoking system

An electrically heated smoking system comprising separate primary and secondary units, the primary unit comprising:

• a primary unit housing, the primary unit housing including:
• a primary power supply, primary circuitry, and
• a docking port including a docking port interface electrically connected to the primary power supply:
• the secondary unit comprising:
• a secondary unit housing configured to receive an aerosol forming substrate, the secondary unit housing shaped to be received in the docking port of the primary unit, the secondary unit housing including:
• at least one heating element within the secondary unit housing, the at least one heating element operable to heat an aerosol forming substrate received by the secondary unit housing when the at least one heating element is supplied electrical power:
• a secondary unit interface electrically connected to the at least one heating element, the secondary unit interface on the secondary unit housing wherein the secondary unit interface is electrically connected to the docking port interface when the secondary unit is in the docking port of the primary unit such that the primary power supply supplies electrical power to the at least one heating element during a pre-heating mode, to increase the temperature of an aerosol forming substrate received by the secondary unit housing to an operating temperature;
• a secondary power supply within the secondary unit housing, the secondary power supply configured to supply electrical power to the at least one heating element during a smoking mode after the pre-heating mode when the secondary unit is separated from the primary unit;
• and
• secondary circuitry within the secondary unit housing, the secondary circuitry configured to control the secondary power supply in supplying electrical power to the at least one heating element during the smoking mode;
• wherein the secondary unit is about the size of a lit-end cigarette such that a user can hold the secondary unit between their fingers in a similar way to a lit-end cigarette;
• further comprising a plurality of secondary units each configured to receive an aerosol forming substrate, wherein the primary unit includes a respective docking port for each of the plurality of secondary units such that the secondary unit interface of each secondary unit may be electrically connected to a respective docking port interface of the respective docking ports;
• wherein the primary unit includes a plurality of electrically connectable modules, each module including a docking port configured to receive a respective secondary unit;
• (a) the plurality of electrically connectable modules are magnetically attachable;
• and/or
• (b) a first module of the plurality of modules includes an external power connection, the first module electrically connected to at least a second module wherein the first module is operable to provide power to the second module.