A device for communicating information regarding an elevator car that moves along a vertical path , the device comprising: at least one sensor configured to be supported on the elevator car and to sense at least one characteristic of the elevator car; a transmitter configured to transmit a wirelessly communicated output indicating at least one condition based on the sensed characteristic, the transmitter being configured to use a first transmit power when the device is at a first location along the vertical path and to use a second, different transmit power when the device is at a second, different location along the vertical path; a controller including a processor and memory , wherein the memory includes indications of a plurality of transmit powers for a plurality of locations along the vertical path, the processor determines the location of the device along the vertical path, and the controller controls the transmitter to use the transmit power indicated in the memory for a current location of the device; and a battery , characterised in that the transmitter is configured to alter a manner in which the transmitter transmits information based on a change in a charge level of the battery, and the transmitter is configured to alter the manner by at least one change selected from the group of changes consisting of changing a heartbeat duty cycle of communications to include longer pauses between communications, reducing a number of locations along the vertical path from which the wirelessly communicated output is transmitted, only transmitting when the device is at a location where the transmit power is below a low battery threshold transmit level, and sending a low battery indication when the battery charge level reaches a preselected threshold. at least one sensor configured to be supported on the elevator car and to sense at least one characteristic of the elevator car; a transmitter configured to transmit a wirelessly communicated output indicating at least one condition based on the sensed characteristic, the transmitter being configured to use a first transmit power when the device is at a first location along the vertical path and to use a second, different transmit power when the device is at a second, different location along the vertical path; a controller including a processor and memory , wherein the memory includes indications of a plurality of transmit powers for a plurality of locations along the vertical path, the processor determines the location of the device along the vertical path, and the controller controls the transmitter to use the transmit power indicated in the memory for a current location of the device; and a battery , characterised in that the transmitter is configured to alter a manner in which the transmitter transmits information based on a change in a charge level of the battery, and the transmitter is configured to alter the manner by at least one change selected from the group of changes consisting of changing a heartbeat duty cycle of communications to include longer pauses between communications, reducing a number of locations along the vertical path from which the wirelessly communicated output is transmitted, only transmitting when the device is at a location where the transmit power is below a low battery threshold transmit level, and sending a low battery indication when the battery charge level reaches a preselected threshold. <EOS>