In each of the band's design mock-ups, the device would have connected to the accessory port on the bottom side of the Apple Watch casing to provide up to an estimated 30 hours of extra battery life. But, as developer Lane Musgrave mentioned in a recent blog post, a lesser-known update in watchOS 2.0.1 has blocked off third-party band manufacturers from taking advantage of the accessory port to fuel the abilities of "smartbands."
Beginning with watchOS 2.0.1 an unexpected change to the Apple External Accessory Protocol disabled the functionality of Reserve Strap. Until this change, Reserve Strap functioned perfectly–extending the battery life of Apple Watch by over 150% in many cases allowing users to keep their Watch charged for up to a week.The developers note that any user who has yet to upgrade to 2.0.1, and seemingly doesn't plan on doing so in the future, can still take advantage of Reserve Strap. The company will ship a device to those customers "in the next few weeks." It's also encouraging users to send an email to the Apple Hardware Evangelism team, and submit feedback on Apple.com, to spread awareness about the lack of an official Apple Watch smartband MFi program.
Specifically, this bug interferes with the communication between accessories and Apple Watch. For the time being, Apple has suspended use of this port until they unveil an official MFi program for Watch. In keeping with their wishes we will also be suspending shipment of all orders until Apple supports development of smartbands.
In March, Reserve Strap also announced the "Reserve Strap LTE," which would allow users to bypass the Apple Watch's need of a Bluetooth-connected iPhone thanks to a micro-SIM card & low power WiFi hotspot built directly into the band. Since the LTE version of the Reserve Strap uses a hotspot to connect to the Apple Watch and wouldn't necessarily require connecting through the accessory port, it could possibly move forward as a full-fledged product, but it's in very early R&D stages at this point.
The company is hoping that an MFi program will launch soon, and looks to a recent patent filing by Apple as a potential indicator of such a move. The patent describes a series of strap designs that have embedded electronic devices -- including batteries, displays, and GPS sensors -- that all connect to the Apple Watch's diagnostics port, hinting that the company could be opening the floodgates to third-party smartband developers in the future.
Given that Apple just launched a new array of bands, and has yet to suggest smartbands could be coming to the first-generation Apple Watch, it's likely such a feature would debut on future versions of the device, such as the Apple Watch 2.