The iPhone XS, XS Max, and XR should deliver even better battery life than its predecessors, with the XR expected to offer the best battery life of the three. There will be cases where the battery will run out before you’ve had a chance to recharge it, which could lead to some unwanted consequences. But Apple has figured out a way to have all three iPhones work even when there’s no battery left, to perform a few specific tasks.
When Apple unveiled the new iPhones last week, it revealed that all of them support a feature called “Express Cards with power reserve,” without really explaining what it was.
It’s a brand new iPhone feature that will let you use the NFC chip even when the battery life is dead. It might not sound like a big deal, but if you’re using your iPhone to pay for transit, or get access to your building, then it really is.
Apple updated its iOS Security documentation with more details about Express Card transactions. The feature works with “a transit card designated as the Express Transit card,” and “student ID cards with Express Mode turned on.” Here’s how it all works:
Pressing the side button displays the low battery icon as well as text indicating Express Cards are available to use. The NFC controller performs express card transactions under the same conditions as when iOS is running, except that transactions are indicated with only haptic notification. No visible notification is shown.
The feature is limited to paying for transit and unlocking doors with student IDs, so you other people may not get to take advantage of it anytime soon.
If the phone is shut down, this always-on support for NFC transactions won’t work. And, before you ask, Apple Pay payments will not work when the phone is out of juice.
The “Express Cards with power reserve” features is not a must-have feature for mobile devices, but it’s a great new trick that might help you out in those rare instances where you’ve run out of battery.