iPhone Charging Slowly? Why It Happens & How to Fix It

Did You Know?

Quick answer: Slow iPhone charging is usually caused by using a low-wattage charger, a worn cable, debris in the charging port, or background apps consuming power while charging. Use a 20W+ adapter, clean the port, and enable Airplane Mode for fastest charging. If your iPhone won't charge at all, see our dedicated guide.

If your iPhone takes hours to charge when it used to be much faster, there are several potential causes. For port hardware issues, see our charging port repair guide. This guide covers everything from simple fixes you can do yourself to hardware issues that may need professional attention.

What's Normal iPhone Charging Speed?

Before diagnosing slow charging, it helps to know what's actually normal for your iPhone model:

Common Causes of Slow Charging

1. Low-Wattage Charger

The most common cause of slow charging is using an underpowered adapter. The 5W adapter that came with older iPhones takes significantly longer than modern 20W+ fast chargers. If you're using a third-party charger, check its wattage.

2. Worn or Damaged Cable

Charging cables degrade over time. Frayed cables, damaged connectors, or internally broken wires reduce power delivery. This is especially common near the connector ends where cables bend repeatedly.

3. Debris in the Charging Port

Lint, dust, and pocket debris accumulate in the charging port over time. This prevents the cable from making a solid connection, reducing charging speed or causing intermittent charging.

4. Background Activity

If you use your iPhone while charging — especially for gaming, video, or GPS navigation — power consumption may exceed the charging rate, resulting in very slow net charging.

5. High Temperature

iPhones reduce charging speed when they get too hot to protect the battery. Charging in direct sunlight, in a hot car, or while using intensive apps triggers this protection. See our iPhone overheating guide for more.

6. Optimised Battery Charging

iOS includes a feature that learns your charging routine and intentionally slows charging above 80% to extend battery lifespan. This is normal behaviour, not a fault.

Troubleshooting Steps

Step 1: Check Your Charger Wattage

For fastest charging, use at least a 20W USB-C Power Delivery adapter:

• 5W — Very slow (old Apple adapter)
• 12W — Moderate (iPad adapter)
• 20W+ — Fast charging (recommended)
• 30W+ — Fastest for iPhone 15 Pro models

Step 2: Test a Different Cable

Try a different charging cable, preferably an Apple-certified (MFi) Lightning or USB-C cable. Non-certified cables may not support full charging speeds and can degrade faster.

Step 3: Clean the Charging Port

Carefully clean the charging port:

• Use a wooden or plastic toothpick (never metal)
• Gently scrape along the bottom of the port
• Use compressed air from a distance to dislodge debris
• A soft brush can remove remaining dust

Warning

Be gentle: The charging port contains delicate pins that can be damaged by aggressive cleaning. If you can see debris but can't remove it safely, professional cleaning is inexpensive and risk-free.

Step 4: Enable Airplane Mode

For fastest charging, enable Airplane Mode and avoid using the phone. This minimises power consumption while charging. You can also turn the phone off completely for maximum charging speed.

Step 5: Remove the Case

Some cases trap heat during charging. If your iPhone feels warm while charging, remove the case to improve heat dissipation and maintain optimal charging speed.

Step 6: Check Optimised Battery Charging

If charging seems to stall at 80%, check Settings → Battery → Battery Health & Charging. "Optimised Battery Charging" intentionally pauses at 80% until you need the phone. You can disable this if needed.

Step 7: Restart Your iPhone

A restart can resolve software issues affecting charging. Hold Side + Volume Down (iPhone X and later) until the power slider appears. Turn off, wait 30 seconds, then turn back on.

Hardware Issues

Charging Port Damage

If cleaning doesn't help and the cable doesn't click firmly into place, the charging port may be damaged. If your iPhone won't charge at all, that's a more serious symptom. Signs of port damage include:

• Cable feels loose or falls out easily
• Charging only works at certain angles
• Charging stops when the phone moves
• Visible damage to the port pins

Battery Degradation

A heavily degraded battery can affect charging behaviour. Check Settings → Battery → Battery Health. If maximum capacity is below 80%, the battery may need replacement regardless of charging speed issues. This also commonly causes fast battery drain.

UK Repair Costs

Frequently Asked Questions

Why does my iPhone charge slowly with some chargers but not others?

Different chargers have different wattage outputs. Your iPhone negotiates charging speed with the charger — a 5W charger will always be slower than a 20W charger regardless of the cable used.

Is it bad to use a third-party charger?

Quality third-party chargers from reputable brands work fine. Look for MFi certification for cables and USB-C PD (Power Delivery) certification for adapters. Avoid very cheap unbranded chargers as they may not meet safety standards.

Why does my iPhone stop charging at 80%?

This is Optimised Battery Charging. iOS learns your daily routine and delays charging past 80% until you need the phone. This reduces battery wear by minimising time spent at 100%. You can disable it in Battery settings.

Can wireless charging be as fast as wired?

Wireless charging is inherently slower than wired. Even with MagSafe (15W), it's slower than a 20W wired charger. Standard Qi wireless charging (7.5W) is significantly slower still. Use wired charging when speed matters.