A method for charging a fully depleted battery of a wireless charging (WLC) device is provided. An RF controller and a read-only non-volatile memory of the WLC device is powered with the RF field of a WLC charger device. The RF controller controls charging of the battery by the RF field using a first charging program stored in the read-only non-volatile memory. A microcontroller of the WLC device is booted up after the battery has reached a predetermined voltage level. The microcontroller loads a second more complex dynamic charging program into a volatile random-access memory (RAM) of the WLC device for execution by the RF controller. The RF controller transitions code execution from the first charging program in the read-only non-volatile memory to the second charging program in the RAM. In another embodiment, the WLC device is provided.