A rechargeable e-cigarette comprising: a battery; a connector which is electrically connectable to an external battery pack; and a recharging mechanism for re-charging the battery using the external battery pack when the connector is electrically connected to the external battery pack, the recharging mechanism comprising: a charge controller for controlling electrical power flow from the external battery pack to the battery; a temperature sensor which is responsive to the temperature of the battery; and a timer; wherein: the charging controller is configured to prevent electrical power flow from the external battery pack to the battery when the temperature of the battery is determined to lie outside a range defined between a lower temperature threshold and an upper temperature threshold; and the timer is configured to start timing when electrical power starts flowing from the external battery pack to the battery and to prevent electrical power flow from the external battery pack to the battery after a predetermined time period has elapsed. a battery; a connector which is electrically connectable to an external battery pack; and a recharging mechanism for re-charging the battery using the external battery pack when the connector is electrically connected to the external battery pack, the recharging mechanism comprising: a charge controller for controlling electrical power flow from the external battery pack to the battery; a temperature sensor which is responsive to the temperature of the battery; and a timer; wherein: the charging controller is configured to prevent electrical power flow from the external battery pack to the battery when the temperature of the battery is determined to lie outside a range defined between a lower temperature threshold and an upper temperature threshold; and the timer is configured to start timing when electrical power starts flowing from the external battery pack to the battery and to prevent electrical power flow from the external battery pack to the battery after a predetermined time period has elapsed. a charge controller for controlling electrical power flow from the external battery pack to the battery; a temperature sensor which is responsive to the temperature of the battery; and a timer; wherein: the charging controller is configured to prevent electrical power flow from the external battery pack to the battery when the temperature of the battery is determined to lie outside a range defined between a lower temperature threshold and an upper temperature threshold; and the timer is configured to start timing when electrical power starts flowing from the external battery pack to the battery and to prevent electrical power flow from the external battery pack to the battery after a predetermined time period has elapsed. the charging controller is configured to prevent electrical power flow from the external battery pack to the battery when the temperature of the battery is determined to lie outside a range defined between a lower temperature threshold and an upper temperature threshold; and the timer is configured to start timing when electrical power starts flowing from the external battery pack to the battery and to prevent electrical power flow from the external battery pack to the battery after a predetermined time period has elapsed.