Evolution of a Voltage-Time Model of Thermal Batteries
Abstract
A temperature time model of thermal batteries has almost been completed and validated against experimental data. This Memorandum first summarises early attempts to integrate a voltage-time model into this, taking advantage of the instantaneous predictions of temperature, thermodynamic potentials, and internal resistance which the thermal model provides. It then describes how recent refinements of the voltage-time model have led to improved simulation of the discharges of a wide range of sizes and types of thermal battery under an equally wide range of test conditions. The semi-empirical approach adopted has been to provide a universally-applicable framework based on logical concepts to cover various effects such as polarisation etc, but with adjustable numerical parameters. It is shown that a moderately good simulation may be obtained for the majority of available discharge curves, using this one set of equations and without altering parameter values. Further improvements can be obtained when parameter values are optimised for one particular type of battery. Comparisons of model simulations against a body of experimental data have pinpointed remaining discrepancies which will guide further refinement efforts.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1991
- Accession Number
- ADA236446
Entities
People
- Jessica H Knight