Apparatus for wireless control and sensing of an emergency luminaire, the apparatus comprising: a power control unit comprising a switch connectable between a power terminal of the emergency luminaire and a lighting circuit for supplying electrical power to the emergency luminaire; a power monitoring module connectable to a battery for supplying electrical power to the luminaire in event of a mains failure, the power monitoring module being configured to measure an output voltage and/ or current of the battery; and a wireless communication module configured to communicate wirelessly with a network, wherein the apparatus is configured to control the switch, in accordance with a control signal received from the network, to control the supply of electrical power to the luminaire from the lighting circuit, and is further configured to transmit information about the measured output voltage and/or current of the battery over the network via the wireless communication module, characterised in that the apparatus further comprises a controller configured to generate a control signal and transmit the control signal to the wireless communication module over the network, to remotely control the emergency luminaire, wherein the controller is configured to perform a testing routine by: controlling the switch to interrupt the supply of electrical power to the emergency luminaire from the lighting circuit; recording a start time at which the supply of electrical power was interrupted; using the power monitoring module, detecting a first current and/or voltage characteristic indicating that a light source of the emergency luminaire has turned off; recording the time at which the first current and/or voltage characteristic was detected; and determining a total discharge time of the battery as the total time elapsed between the start time and the time at which the first current and/or voltage characteristic was detected. a power control unit comprising a switch connectable between a power terminal of the emergency luminaire and a lighting circuit for supplying electrical power to the emergency luminaire; a power monitoring module connectable to a battery for supplying electrical power to the luminaire in event of a mains failure, the power monitoring module being configured to measure an output voltage and/ or current of the battery; and a wireless communication module configured to communicate wirelessly with a network, wherein the apparatus is configured to control the switch, in accordance with a control signal received from the network, to control the supply of electrical power to the luminaire from the lighting circuit, and is further configured to transmit information about the measured output voltage and/or current of the battery over the network via the wireless communication module, characterised in that the apparatus further comprises a controller configured to generate a control signal and transmit the control signal to the wireless communication module over the network, to remotely control the emergency luminaire, wherein the controller is configured to perform a testing routine by: controlling the switch to interrupt the supply of electrical power to the emergency luminaire from the lighting circuit; recording a start time at which the supply of electrical power was interrupted; using the power monitoring module, detecting a first current and/or voltage characteristic indicating that a light source of the emergency luminaire has turned off; recording the time at which the first current and/or voltage characteristic was detected; and determining a total discharge time of the battery as the total time elapsed between the start time and the time at which the first current and/or voltage characteristic was detected. controlling the switch to interrupt the supply of electrical power to the emergency luminaire from the lighting circuit; recording a start time at which the supply of electrical power was interrupted; using the power monitoring module, detecting a first current and/or voltage characteristic indicating that a light source of the emergency luminaire has turned off; recording the time at which the first current and/or voltage characteristic was detected; and determining a total discharge time of the battery as the total time elapsed between the start time and the time at which the first current and/or voltage characteristic was detected.