Why are BMS DC-DC converters extremely sensitive to inductor thermal behavior?
In battery management systems, DC-DC converters are often installed inside battery packs where ambient temperature is significantly higher than in typical ECU environments. Elevated temperature directly reduces magnetic core permeability, which shifts the DC bias curve of the inductor and lowers its effective inductance under load. As inductance drops, ripple current increases, leading to higher MOSFET stress, elevated switching losses, and additional self-heating. This thermal feedback loop can accelerate aging and reduce long-term reliability. For BMS designs, inductors must therefore be evaluated not only at room temperature, but across the full battery pack thermal envelope, including worst-case hot-spot conditions.