Evaluating batteries for advanced wildlife telemetry tags

The authors evaluate miniature batteries as potential power sources for advanced wildlife telemetry tags. These tags are often based on integrated ultrahigh frequency transceivers that are designed for wireless sensor networks and that consume 18–85 mA while receiving or transmitting. This current drain is challenging for many types of miniature batteries. The authors evaluate batteries both on actual tags and in a specialised synthetic‐load circuit. The evaluation focuses on the total amount of energy that the battery delivers until the tag fails, but the authors also investigate other important issues, such as the ability to withstand immersion in water. The main findings are that zinc‐air cells designed mainly for hearing aids perform extremely well in terms of effective energy density (but are hard to deploy), that lithium coin cells require a reservoir capacitor to deliver their rated energy (which is about half of that of zinc air with the same weight) and that rechargeable lithium polymer cells perform well even without a reservoir capacitor.