Triage by symptom
| Symptom | First safe action | Escalate when |
|---|---|---|
| No charging icon | Try a wall outlet, another known-good cable, and inspect the port for debris. | There is liquid, bent hardware, heat, or no response after the charge-and-restart sequence. |
| Stops around 80% | Check temperature, Optimized Battery Charging, or a Charge Limit setting. | The phone is cool and settings do not explain the limit. |
| Black screen | Charge for 30 minutes, then force restart using Apple’s button sequence. | It remains blank, vibrates without display, or shows physical damage. |
| Battery falls quickly | Open Settings > Battery and identify the highest-use apps or a recent setup/update period. | Drain continues after the phone settles, or the device becomes hot or swollen. |
Evidence boundary
Confirmed
- Apple lists dual batteries, USB-C fast charging, MagSafe, and Qi2 support for iPhone Duo.
- Apple’s support sequence includes a wall outlet, cable and adapter checks, port inspection, 30 minutes of charging, and a force restart.
Needs context
Provisional
- A new device may show unusual battery use during setup, indexing, downloads, or restoration; the official pages do not establish a fixed settling period for every user.
Questions covered here
FAQ
Is an 80% limit automatically a failed battery?
No. Apple lists Optimized Battery Charging, temperature, and a charge limit as possible explanations. Check those before treating it as a hardware fault.
Can I use any 60W USB-C charger?
Use a safe, compatible USB-C power adapter and cable. Apple’s specification describes fast-charge conditions, but exact third-party accessory quality still matters.
Primary reading
Sources
- Apple iPhone Duo specificationsPower, charging, and battery claims.
- If your iPhone or iPod touch won't chargeApple’s charging troubleshooting sequence.
- If your iPhone won't turn on or is frozenApple’s restart and service escalation sequence.