A battery-less sensor device includes a sensor to sense an environmental condition, a power supply system, a memory, a communication device, and a processor. The power supply system includes energy harvesting devices to harvest energy from ambient energy sources for powering one or more components of the sensor device, and an energy storage device to store harvested energy. The memory stores sensor data associated with the environmental condition sensed by the sensor. The communication device transmits the sensor data to a BMS or remote device. The processor is configured to dynamically select one or more energy sources from the ambient energy sources to power one or more components of the sensor device according to an availability of energy from the ambient energy sources and/or an energy consumption requirement of the one or more components of the sensor device, and to control supply of power to the one or more components.