What are the thermal management challenges for EV battery packs?

Key challenges include: Maintaining optimal temperature range (20-40°C) for performance and longevity, Managing temperature uniformity (ΔT<5°C) across cells to prevent uneven aging, Handling high heat loads during fast charging (2-3x normal), Preventing thermal runaway propagation between cells, Cold weather pre-conditioning requiring heating, Balancing cooling system weight/cost against performance, and Integration with cabin HVAC. Solutions include liquid cooling (glycol loops, cold plates), air cooling (limited to lower power density), phase change materials, and refrigerant direct cooling. Tesla uses serpentine ribbon coolant channels; Chevrolet Bolt uses aluminum cold plates.