A wireless charging circuit is disclosed. In this regard, a wireless charging circuit is configured to charge a battery by harvesting radio frequency (RF) power from a wireless RF charging signal provided by a wireless charging station. The wireless charging circuit monitors an effective charging power provided to the battery and sends a battery charging signal indication (BCSI) to the wireless charging station to reduce the effective charging power if the effective charging power is greater than a target charging power. In another aspect, the wireless charging circuit sends the BCSI to increase the effective charging power if the effective charging power is less than the target charging power. By dynamically adjusting the effective charging power based on the charging profile of the battery, it is possible to provide fast charging to the battery while protecting the battery from overcharging damage.