An injection device for administering a dose of a liquid medicament, comprising: - an elongated housing having a dispensing end and being configured to accommodate a cartridge filled with the liquid medicament, - a drive mechanism configured to operably engage with the cartridge for expelling of a dose of the medicament from the cartridge via the dispensing end, - a protective cap releasably attachable to the housing to cover the dispensing end, - a first electronic circuit attached to the protective cap and electrically connected to at least a first cap electrode (32, 33, 34) arranged on the protective cap, wherein the first electronic circuit comprises a first battery, - a second electronic circuit arranged inside the housing, coupled to the drive mechanism and electrically connected to at least a first housing electrode (62, 63, 64) that is located on the housing, wherein the second electronic circuit comprises a second logic circuit to capture dose dispensing related data from the drive mechanism, - wherein the first and the second electronic circuits (40, 60) are electrically connected to each other via the at least first cap electrode (32, 33, 34) and the at least first housing electrode (62, 63, 64) that are in mutual contact when the protective cap is attached to the housing, - characterized in that the second electronic circuit is configured to transmit captured data to the first logic circuit via the at least first cap electrode (32, 33, 34) and the at least first housing electrode (62, 63, 64), and in that - the first electronic circuit comprises a logic circuit to process electric signals received from the second electronic circuit. - an elongated housing having a dispensing end and being configured to accommodate a cartridge filled with the liquid medicament, - a drive mechanism configured to operably engage with the cartridge for expelling of a dose of the medicament from the cartridge via the dispensing end, - a protective cap releasably attachable to the housing to cover the dispensing end, - a first electronic circuit attached to the protective cap and electrically connected to at least a first cap electrode (32, 33, 34) arranged on the protective cap, wherein the first electronic circuit comprises a first battery, - a second electronic circuit arranged inside the housing, coupled to the drive mechanism and electrically connected to at least a first housing electrode (62, 63, 64) that is located on the housing, wherein the second electronic circuit comprises a second logic circuit to capture dose dispensing related data from the drive mechanism, - wherein the first and the second electronic circuits (40, 60) are electrically connected to each other via the at least first cap electrode (32, 33, 34) and the at least first housing electrode (62, 63, 64) that are in mutual contact when the protective cap is attached to the housing, - characterized in that the second electronic circuit is configured to transmit captured data to the first logic circuit via the at least first cap electrode (32, 33, 34) and the at least first housing electrode (62, 63, 64), and in that - the first electronic circuit comprises a logic circuit to process electric signals received from the second electronic circuit.