Hidden port for Apple Watch can be used to charge it, perhaps more

Tucked inside the Apple Watch is a little secret if you know where to look: There's a 6 pin port in the watch case that's normally hidden by the watch strap. The Apple Watch's port is for diagnostics but it's actually capable of more, notes 9to5 Mac.

One third-party strap maker already found you can charge the Apple Watch faster using a wired cable and the hidden port, for example.

The group behind Reserve Strap, an Apple Watch strap with embedded battery cells, is already redesigning its original product based on the port's capabilities:

We've developed and tested a completely rethought design that takes advantage of the 6 pin port underneath the band slide of the Apple Watch. This port hadn't been deciphered by anyone until now but we've been able to make significant enough observations so far to warrant shifting our development focus to this new method.

Depending on what can be done with the port, this development opens up a market for other third-party Apple Watch straps that can use it. Indeed, that approach reminds me a bit of Pebble, a competing smartwatch that works with both iOS and Android devices.

A few days after Pebble announced its new Pebble Time watch, the company said it would support third-party accessories built into straps so that Pebble could gain additional capabilities. One example is a possible watch strap with an embedded GPS radio, adding precise location data to the Pebble Time.

While Pebble is embracing the idea of third-party accessory integration, Apple has kept mum on the diagnostic port. The company hasn't called any attention to it, nor has it announced any "Made for Apple Watch" type of certification program.

With the port's existence, however, it could. And even if Apple doesn't, the Reserve Strap team looks to be moving forward by using the port anyway, hoping to add both faster charging and up to 120 percent more battery life for the Apple Watch.

Related: Cool Apple Watch accessories to help you customize it