Energy Budgeting for Battery-Powered Sensors with a Known Task Schedule

Battery-powered wireless sensors are severely constrained by the amount of the available energy. A method for computing the energy budget per sensing task can be a valuable design aid for sensor network optimizations. This work presents such a method that computes the upper and lower bounds on the task energy budget for a sensor node that must remain operational over a specified lifetime, with a known task schedule. These bounds take into account nonlinear changes in the battery voltage, capacity loss at high discharge rates, charge recovery, and capacity fade over time. We also propose efficient approximations replacing expensive calculations of the battery voltage while computing the energy budget bounds