Let us take a look at what silicon is so heavily guarded by the charging case:

STMicroelectonics STM32L072 ARM Cortex-M0+ MCU

NXP Semiconductor CBTL1610A3 charging/port controller IC (as seen in iPhones 6s and SE and both iPad Pro models)

Texas Instruments BQ24232 power management IC

Maxim Integrated MAX9028 1.8 V comparator

AMS AS3441 power and communication interface (likely)

Probably ON Semiconductor regulators