A method for estimating state of charge in energy-aware wireless sensor nodes

Aleksandar Nikolic92, Blagoje Babic92, Aleksandar Zigic92, Nikola Miladinovic92, Srdjan Milosavljevic92 The state of charge estimate of a lithium-based battery is not trivial. Accurate measurements of this quantity require the implementation of complex and expensive, in terms of energy, measuring systems. In a wireless sensor node these methods need to be implemented on-board, thus the energy consumed by the measurement system must be negligible. In this paper we propose a method based on a virtual Coulomb counting, which is able to provide enough accuracy while maintaining negligible the power consumed by the node. Nevertheless it requires a preliminary characterization of the sensor node behavior through laboratory tests.