By activating a dormant software lock on their newest iPhones, Apple is effectively announcing a drastic new policy: only Apple batteries can go in iPhones, and only they can install them.
If you replace the battery in the newest iPhones, a message indicating you need to service your battery appears in Settings > Battery, next to Battery Health. The “Service” message is normally an indication that the battery is degraded and needs to be replaced. The message still shows up when you put in a brand new battery, however. Here’s the bigger problem: our lab tests confirmed that even when you swap in a genuine Apple battery, the phone will still display the “Service” message.
It’s not a bug; it’s a feature Apple wants. Unless an Apple Genius or an Apple Authorized Service Provider authenticates a battery to the phone, that phone will never show its battery health and always report a vague, ominous problem.