Try a different Apple or MFi-certified cable and power adapter in a wall outlet, gently clean lint from the Lightning/USB-C port with a wooden toothpick, force-restart the iPhone, and check if Optimized or 80% charging is pausing it. If it's hot or cold, let it reach room temperature.

The short explanation

Pocket lint packs into charging ports and stops the plug seating fully, which is the most common cause. iOS also pauses charging on purpose: Optimized Battery Charging holds at 80% until shortly before you generally unplug, iPhone 15 and later can cap charging at 80%, and charging pauses when the phone is too hot.

A message saying the accessory isn’t supported, or “Liquid detected in Lightning/USB-C connector”, also stops charging until the problem is fixed.

Symptoms

  • Battery icon shows no lightning bolt when plugged in.
  • “Not Charging” or charging stops at 80%.
  • “This accessory may not be supported” or liquid detected alert.

Why it happens

  • Lint or debris in the charging port.
  • Damaged or uncertified cable/adapter.
  • Optimized Charging, 80% limit or high temperature.
  • Software glitch or worn battery/port.

Try these fixes

  1. Try another cable, adapter and outletUse an Apple or MFi-certified cable and a wall adapter, not a computer USB port.
  2. Clean the portPower off and shine a light into the port. Gently remove lint with a wooden or plastic toothpick. Don't use metal or liquids.
  3. Force restartPress and release Volume Up, press and release Volume Down, then hold the side button until the Apple logo appears.
  4. Check charging settingsSettings → Battery → Charging (or Battery Health & Charging): see if Optimized Charging or an 80% limit is active.
  5. Mind the temperatureRemove thick cases and let a hot or cold phone return to room temperature.
  6. Liquid alertUnplug, tap the iPhone gently with the connector facing down, and leave it in a dry, ventilated place for at least 30 minutes.
  7. Check battery healthSettings → Battery → Battery Health. Book Apple service if it says Service, or if the port is damaged.
Check it's fixed: The lightning bolt appears and the percentage rises steadily.

Avoiding it in future

Keep the port clean, use certified accessories, and avoid charging in heat.