Since its inception, the Apple Watches diagnostic port was a mystery part of the wearable line. But the new Series 7 has officially dropped the six-pin port.
MacRumors first noticed the absence of a port when they removed the bottom strap from the Apple Watch Series 7. The company has now removed the hidden plate as well as the port. The port was intended for internal diagnostics and wasn't acknowledged by Apples documentation or website. The diagnostic port did hint at the possibility that the Apple Watch could be expanded with hardware accessories.
The Reserve Strap is the most well-known of these. It attempted to extend the battery life of Apple Watches by using the port to charge extra batteries. This was done by making a special band that would fit directly into the diagnostic port. It actually charged faster than Apple's magnetic cable.
Apple quickly stopped this capability and the Reserve Strap (alongside virtually all other attempts at harnessing it for useful purposes). It was still useful for its original purpose, which was to provide diagnostics and repair services for Apple internal devices.
Apple still needs to perform diagnostics on its Apple Watch. Apple appears to be replacing that mysterious port with a 60.5GHz wireless module capable of local data transfer. Some speculate that Apple may be testing a portless iPhone with similar technology that can replace cables that connect to a computer. However, years of using a useless diagnostic port to diagnose problems have shown us that there is sometimes no better meaning or utility in proprietary diagnostic tools.
Updated October 13, 2005, at 5:17pm