Poster: Towards an Accurate Lifetime Estimation of Battery-Free Sensor Nodes Powered by Supercapacitors.

Recent advances in energy-harvesting and low-power components have led to the emergence of battery-free sensor nodes that rely solely on ambient energy and environmentalfriendly supercapacitors as energy storage. Accurately estimating the lifetime of these sensor nodes is crucial to guarantee that they can also operate in periods where no ambient energy is available, yet very complex. In this poster, we show experimentally that off-the-shelf supercapacitors have large capacitance tolerances and exhibit complex discharging characteristics due to leakage and charge-distribution effects. We argue that these cannot be neglected and that empirical data profiling the characteristics of supercapacitors is essential towards an accurate estimation of the system's lifetime.