For the ROG STRIX X570-I Gaming motherboard, the RTC CMOS battery is located on top of the group of ports just to the left of the Wi-Fi Antenna ports. It is packaged in shrink wrap and held there with strong two sided foam tape. Battery type is 3V Lithium CR2032 with 6.5cm long cable with Molex 51021 2pin female connector, pin one positive. Access the backside of the motherboard to remove 2 screws securing the back half of the VRM heatsink assembly. You may need to remove the board from the chassis to get at that. Then remove the NVME heatsink, VRM fan screen, and rear I/O top cover/bracket. Remove CPU Cooler if it is blocking removal of the VRM heatsink. Being careful not to damage the cable for the VRM fan, gently remove the top half of the VRM heatsink assembly. The RTC CMOS Battery is now visible. It's cable is taped down and the battery is in heat shrink package.