Design and development of heat pipe cooling systems for air & watertight Portable Energy Storage units

Portable Energy Storage (PES) units play a vital role in delivering reliable and sustainable energy solutions, particularly in regions with limited grid access or challenging environmental conditions that require special Ingress Protection (IP) considerations, such as air and watertight designs without vents. Thermal management is a critical challenge for such PES units, especially for key components such as inverters and battery packages, which are prone to overheating. This study explores the integration of heat pipe-based cooling systems with heatsinks as an effective thermal management solution. A 1-kW PES was designed, developed and assessed as a case study under varying ambient temperatures and operational scenarios. Both free and forced convection cooling methods were evaluated through experiments and validated simulations. Results show that under free convection at an ambient temperature of 23 °C, Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) remained below 70 °C, while Lithium-ion Batteries (LIBs) stabilized at 60 °C. Forced convection with 1.4 W fans significantly improved cooling efficiency, reducing temperatures by 25–45 %, depending on ambient conditions. At 23 °C, a 33 % temperature reduction was observed in both MOSFETs and LIBs. At an ambient temperature of 50 °C, MOSFETs were maintained at 70 °C, and LIBs remained below 60 °C for ambient temperatures up to 45 °C. These findings confirm that heat pipe cooling systems, combined with forced convection, offer an effective thermal management solution for compact, air and watertight PES applications.