An apparatus comprising a power providing arrangement for a field powered device having a coil antenna for receiving a wireless signal, the power providing arrangement comprising: a rectifier configured to rectify the wireless signal received via the coil antenna; a first capacitor and a second capacitor configured to be coupled to the coil antenna via the rectifier; the second capacitor arranged in parallel with the first capacitor via a switch; the switch providing at least (a) a disconnected state in which the second capacitor is disconnected from the first capacitor, wherein the first capacitor is configured to store energy obtained from the wireless signal received by the coil antenna, up to a first stored energy level, and provide said energy to power the field powered device in a first mode; and (b) a connected state in which the first capacitor and the second capacitor are connected in parallel and configured to both store the energy obtained from the wireless signal up to a second stored energy level, greater than the first stored energy level, and configured to provide said energy to power the field powered device in a second mode, different to the first mode; characterized in that the switch is configured to transition from the disconnected state to the connected state based on particular signalling received from a remote device wherein the particular signalling is received via the coil antenna and comprises a request from the remote device to close the switch. a rectifier configured to rectify the wireless signal received via the coil antenna; a first capacitor and a second capacitor configured to be coupled to the coil antenna via the rectifier; the second capacitor arranged in parallel with the first capacitor via a switch; the switch providing at least (a) a disconnected state in which the second capacitor is disconnected from the first capacitor, wherein the first capacitor is configured to store energy obtained from the wireless signal received by the coil antenna, up to a first stored energy level, and provide said energy to power the field powered device in a first mode; and (b) a connected state in which the first capacitor and the second capacitor are connected in parallel and configured to both store the energy obtained from the wireless signal up to a second stored energy level, greater than the first stored energy level, and configured to provide said energy to power the field powered device in a second mode, different to the first mode; (a) a disconnected state in which the second capacitor is disconnected from the first capacitor, wherein the first capacitor is configured to store energy obtained from the wireless signal received by the coil antenna, up to a first stored energy level, and provide said energy to power the field powered device in a first mode; and (b) a connected state in which the first capacitor and the second capacitor are connected in parallel and configured to both store the energy obtained from the wireless signal up to a second stored energy level, greater than the first stored energy level, and configured to provide said energy to power the field powered device in a second mode, different to the first mode;