Last week, YouTuber Justin Ashford swapped the original battery in an iPhone XR with one he bought from an electronics market in Shenzhen. Ashford runs a channel called TheArtofRepair, which features videos about repairing electronics. This latest repair video wasn’t just an ordinary battery swap. It was a pointed message to Apple.

The external battery he put into the iPhone XR, Ashford says, was an “original” iPhone battery—meaning, it was the same battery pack you’d find if you cracked open your shiny new 2018 iPhone. But after the swap, when Ashford went into the battery section of the iPhone’s settings, he noticed an alert: “Service.”

Normally, if you tap on the iPhone's “Battery Health” settings, you'd see a measurement of your battery’s maximum capacity, but that’s it. Ashford’s battery swap had changed the language.

The video caught the eye of iFixit, a computer repair company based in San Luis Obispo, California. Besides repairing stuff, iFixit publishes blog posts that expose the inner workings of gadgets, sometimes to the chagrin of electronics manufacturers. “We were able to replicate it on an iPhone XS running both iOS 12 and the iOS 13 beta,” iFixit writer Craig Lloyd detailed in a post, less than 24 hours after Ashford’s video published. Dig even deeper into the “Service” alert after swapping your battery, Lloyd wrote, and you’ll find an “important battery message” that says Apple is “unable to verify that this iPhone has a genuine Apple battery.”

To the average consumer who decides to take a repair into their own hands, ordering a new battery and swapping it themselves, the “Service” alert is likely little more than another setting to be ignored. In short: It’s likely to still work, unless you’ve purchased a total dud.

But to people like Ashford and the team at iFixit, the “Service” warning represents another shot across the bow in the larger conflict around electronics repairs. The Right-to-Repair movement, which advocates for laws that allow people to more easily fix the products they own, has gained traction across the US. Meanwhile, electronics makers and industry lobbyists insist that DIY repairs could result in security vulnerabilities, fire hazards, or downright faulty products.

Battery Basics

Apple’s battery health measurement tool for iPhone, which shows how well your battery performs as it ages, rolled out with iOS 11.3 in March of 2018. The “Service” warning appears only on the newer iPhone XS, iPhone XS Max, and iPhone XR. That means the warnings have been enabled since those phones came out last fall, but most people wouldn't have noticed until now, since most consumers don’t need to replace their new iPhone batteries within the first year of ownership.

“We did our teardown when the new iPhones came out, but we didn’t put in a different battery at the time, because why would we?” says Kyle Wiens, the co-founder and chief executive of iFixit. “It’s after 12 to 14 months [of usage] that people start to look for battery swaps.”

Ashford and the iFixit team also noted that Apple built a proprietary version of a microcontroller into its battery cells, one that sends information about the battery to the phone’s operating system. This kind of chip is not uncommon in modern smartphone batteries, but as the custom-designed chips within gadgets get better and smarter, there’s concern that these could be used to further lock down the products people own.

On Apple’s own website, the company acknowledges that some degradation is to be expected over time. After all, these are lithium ion batteries. But the section about the “Important Battery Message” that might pop up on your phone is just as vague as the message that appears in the iPhone settings itself. “If you see the message below, it means the battery in your iPhone is unable to be verified. This message applies to iPhone XS, iPhone XS Max, and iPhone XR,” Apple’s support page reads. Following that, Apple suggests contacting an authorized Apple service provider. A link leads to Apple’s official support and repair page.