There is a rapidly increasing interest in energy sources optimized to provide electrical energy at high power levels for short times. Applications include very short pulses for digital electronic devices, the somewhat longer power pulse demands of some implantable medical devices and the much larger transient power needs in connection with vehicle traction. Several mechanisms can be used to provide short term energy with fundamentally different characteristics and applicability to different types of transient output requirements. Four different electrochemical methods can be used to evaluate the critical materials parameters in insertion reaction materials that might be applicable to such applications and spreadsheet techniques can be used to model the transient transport behavior of such electrodes under various conditions.