You may notice when connecting a USB-C to Lightning Cable to the PS3-METERC3 that the LED display will light up and act like a device is connected and charging, even if nothing is connected to the Lightning end of the cable. 

This is due to to Apple's MFi certification process with Lightning accessories and cables. The MFi certification is a strict set of requirements that ensure that third party devicess will be compatible with all Apple devices that use the Lightning connector. This MFi certification involves a chip built into the cable which verifies the MFi certification before it allows data or power to passthrough. The chip is what triggers the PS3-METERC3 to “detect” a device, even if one is not connected to the end of the cable.

There is nothing we can do about this particular behavior, so it is important to know this for the purposes of power allocation. If a Lightning cable is connected to any of the USB-C ports, it will be counted as a device connected to that port, which can impact the amount of power dedicated to other ports. For details on power allocation, check out the article here.

For more details on Apple MFi, check out Apple's page on it here.