Shortly before the Apple Watch went up for sale last year, we learned about a little data port that was hiding under one of the strap connectors. At first it seemed like this hardware might be reserved for development models, but the smartwatch ended up keeping the interface for its final form. And while Apple itself didn’t offer any consumer-facing uses for the port, it wasn’t long before we learned about a third-party company interested in taking advantage of the connector, in the form of the battery-boosting Reserve Strap. By tapping into those pins, the strap was supposed to help recharge the Apple Watch while it was in use, extending times between wired charging sessions. Unfortunately, Reserve Strap has hit an insurmountable obstacle, as an Apple watchOS update has blocked its ability to function.
A few days back the Reserve Strap team posted an update on their progress, informing pre-order customers of the bad news. A change to the way software’s able to access the Apple Watch accessory port has rendered Reserve Strap inoperable, no longer capable of powering the smartwatch.
The team’s optimistic that Apple taking this step may hint at future official support for bands that communicate with the smartwatch over this port, but Apple’s yet to commit to anything along those lines. It’s entirely possible that Apple’s just locking things down with no plans to ever formally support something like the Reserve Strap.
Building a product around a not-officially-supported interface is always a gamble, and especially so when you’re dealing with control-loving Apple. This time, it looks like Reserve Strap rolled the dice and lost.