Used iPhone battery suddenly shows as non-genuine. What should I check?

First check the battery information in the iPhone’s own Settings, rather than relying on a shortcut or another battery-reporting app. Those tools can interpret diagnostic data differently from the built-in display. If Settings itself shows a parts warning, take a screenshot and ask the seller to explain it.

A non-genuine warning can be a sign that the battery was replaced or that the phone can’t verify the part. It doesn’t, by itself, prove the battery is counterfeit. A seller’s claim that the phone was never opened is worth checking against the device’s parts and service history, where available, and the built-in battery status.

Don’t reset the phone just to clear the message. Back up your data, then contact the seller and ask for a return, repair, or written explanation while any buyer protection still applies. If the warning remains, an authorized service provider or a reputable repair shop can inspect the battery and tell you what they can verify.

Battery health percentages can differ between diagnostic data and what the phone displays, and readings may change after calibration. That could explain a percentage mismatch, but it doesn’t establish why a genuine-status label changed. Keep an eye on the built-in status and prioritize inspection if you notice swelling, unusual heat, or abrupt shutdowns.