iPhone Charging Slowly? Here's How to Fix It

Start with the simplest reversible checks before moving to resets or repair.

Why this happens

Do not assume the most expensive failure first. This problem usually becomes much easier once you separate a settings problem from a connection, app, accessory or hardware problem.

• A low-power wired or wireless charger can charge normally but slowly.
• iPhone slows charging as it gets fuller to reduce battery stress.
• High or low temperature can make iOS slow or pause charging.
• Optimized Battery Charging or a charge limit can intentionally stop or delay charging above a set level.
• A dirty/damaged cable, adapter or port can reduce power.

Fix it in this order

1. Open Settings → Battery and check for a Slow Charger or Charging on Hold message.
2. Use a compatible charger and cable connected to a wall outlet.
3. Move the iPhone to a cooler environment if it is warm; remove a heat-trapping case during testing.
4. Check the charging port and connector for damage or debris.
5. Restart the iPhone if charging behavior suddenly changed.
6. Review Optimized Battery Charging or Charge Limit settings before assuming 80% is a failure.
7. Compare charging speed from a low battery level rather than only the final 10–20%.

How to identify the real cause

A phone that charges quickly when cool and below 80% but slows near full is often behaving normally. A phone that remains extremely slow at 20–40% with a capable charger deserves cable, port and power-adapter testing.

Common mistakes that waste time

• Treating the final 20% as if it should charge at the same speed as the first 20%.
• Using a weak computer USB port and comparing it with fast wall charging.
• Cooling a hot iPhone with ice or a freezer.
• Turning off battery-health features without first understanding why charging paused.

When this is probably not a settings problem

Seek service if multiple known-good chargers/cables fail, the port is loose or damaged, liquid/corrosion is present, or the phone becomes abnormally hot during ordinary charging.

If you need repair or manufacturer support, write down what you already tested. A short list of known-good cables, devices, networks or apps you tried is much more useful than saying only that the feature “doesn't work.”

Use Battery settings as evidence

Recent iOS versions can surface charging information such as a Slow Charger or temperature-related message. That is more useful than estimating speed by feel. Pair that message with a controlled 15-minute test at a lower battery percentage.

Heat changes the result

Fast charging generates heat, and iPhone may reduce power when temperature rises. A charger can therefore be capable of fast charging at first and then slow later. Test in a normal indoor environment before concluding that the adapter is defective.