Reconsidering batteries in energy harvesting sensing

For the past decade, the status-quo for energy harvesting sensors has been to buffer small amounts of energy in capacitors to intermittently work through a sensing task. While using capacitors for storage offers these systems indefinite lifetime, it comes at a cost - they must tolerate the decreased availability, lower energy utilization, and more complex programming models inherent to a volatile, intermittent design. We argue that many of these problems stem from insufficient energy storage and could be eliminated with the use of batteries. Recent advances in rechargeable battery technology weaken the historical arguments against their use. We believe that using batteries in energy harvesting sensors will push us closer to a class of reliable, general purpose devices that can better serve human-centric sensing applications than their capacitor-based counterparts at the cost of having a finite, but long, lifetime.