Thermal analysis and modeling of a notebook computer battery

Thermal performance of an intelligent notebook computer battery-pack (IBA2+™, Hewlett Packard) was evaluated during operation at 42 °C using a combination of thermal analysis and modeling. The battery-pack was charged at 2.36 A and provided 55-W constant power during discharge. Results showed the battery-pack has reasonable heat dissipation capability except that the temperature rise of its charge control IC increases to 67 °C, which is near the critical thermal limit of the device (73–75 °C). Autopsy results showed this IC has a small die to die-pad size ratio and also large volume of mold compound causing the device self-heating during the charge control process. Thermal modeling provided a detailed understanding of the thermal response of the battery under various operating conditions that helped to reduce the product design cycle-time. The overall results indicated that the battery temperature rise during charge is dominated by the power dissipation from the control electronics and during discharge by the heat dissipation from Li-ion cells.