Battery knowledge · Thermal management and heat transfer
Adiabatic and isothermal conditions
Two idealised thermal boundaries used in testing. Adiabatic means no heat escapes, so every joule raises the sample’s temperature — the principle of accelerating rate calorimetry and the worst case for a pack whose cooling fails. Isothermal means the sample is held at constant temperature while the heat it releases is measured, as in isothermal calorimetry.
- Also called
- adiabatic, isothermal
Example
Heat approaches an equilibrium
Steady rise: 10 K. Time constant: 8.333 min.
C_th = 500 J/K, fixed ambient and heat input, uniform temperature.
Explore the graph
Thermal resistance sets the steady temperature rise; thermal mass sets the response time.
Steady rise: 10 K. Time constant: 8.333 min.
ΔT = P R_th [1 − exp(−t / (C_th R_th))]
Illustrative model. C_th = 500 J/K, fixed ambient and heat input, uniform temperature.
Use in Lemonergy
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References & further reading
Further reading on this topic
These sources provide broader context; they are not presented as citations for every statement in this entry.
- A General Energy Balance for Battery Systems
Dawn Bernardi, Ellen Pawlikowski, John Newman · Journal of The Electrochemical Society · 1985
Topic background · Battery energy balance and irreversible and reversible heat contributions. Reduced thermal models require explicit assumptions and current-sign conventions.
- University Physics Volume 2, §1.6: Mechanisms of Heat Transfer
OpenStax, Rice University
Topic background · Conduction, convection, radiation and thermal resistance.