How can I improve my iPhone's charging speed with iOS 18

New Charging Limit Customization in iOS 18

iOS 18 introduced extended options for setting charging limits beyond the existing 80% cap. Users can now choose to limit the charge to 85%, 90%, or 95%, allowing more flexibility in balancing battery health preservation with charging speed and capacity. Previously, charging would slow down as it approached 80% to protect battery longevity, but with these new options, users on iPhone 15 and later models can charge to higher percentages quickly without waiting for gradual topping off. This feature helps users get more use time between charges while managing battery degradation risks. However, the full benefit of this feature is currently available primarily on iPhone 15 and 16 models, though there are workarounds for older devices.

Identifying Slow Charger Warnings

In iOS 18 and later, iPhones provide explicit feedback on charging speeds directly in the Settings under Battery and on the Lock Screen. A "Slow Charger" message will appear if the charging speed is below the iPhone's maximum supported rate, helping users identify when their charger or cable is insufficient or when system conditions are throttling charging speed. This feature encourages users to switch to higher-wattage chargers or better cables to improve charging speed.

Use the Right Charger and Cable

One of the most important hardware practices to improve charging speed with iOS 18 is using an appropriate charger and cable combination:

- For iPhone 15 and later models, use a USB-C Power Delivery charger combined with a USB-C to USB-C cable (if fully USB-C-enabled) or a USB-C to Lightning cable for earlier models.
- For wired charging, chargers providing at least 20 watts are recommended for newer devices, with higher wattages (e.g., 30W or 35W) supporting even faster charging.
- For wireless charging, use a MagSafe Charger or certified Qi2 wireless charger to maximize wireless charging speeds. Older Qi1 chargers or those with less than 10 watts might slow charging down.
- Be aware that multi-port chargers might reduce power output for each port depending on the number of connected devices and system power management.
- Charging from USB hubs, car ports, or others not delivering sufficient power can result in slower charging.

Minimize Usage While Charging

Active iPhone use during charging significantly slows down charging speed as power is diverted to running apps and maintaining the display. Intensive activities like gaming, video streaming at high quality, or camera use generate heat and require processing power, which reduces charging efficiency.

To optimize charging speed:
- Limit app usage during charging.
- Avoid using graphics or CPU-intensive apps.
- Reduce screen brightness to minimize power consumption.
- Turn on Low Power Mode to reduce background activity and system resource use while charging.

Temperature Management

Optimal charging performance requires keeping the iPhone at a moderate temperature. Charging generates heat, and iPhones will slow or pause charging if temperatures exceed safe operating thresholds to protect battery health.

Tips for temperature management:
- Charge the phone in a cool environment.
- Remove phone cases that cause overheating.
- Avoid charging in direct sunlight or hot surroundings.
- iOS will indicate if charging is on hold due to temperature in Settings > Battery.

Use Automation and Shortcuts for Faster Charging

A practical way to speed up charging is by automating power-consuming settings when the iPhone is plugged in. For example, creating an automation using Shortcuts to:

- Disable Wi-Fi and Bluetooth while charging.
- Enable Low Power Mode.
- Lower screen brightness to minimum during charging.

When unplugged, the automation can revert these settings to normal. This approach reduces background activities and connectivity power drain instantly when charging begins, maximizing power available for charging.

Disable Optimized Battery Charging Temporarily

Optimized Battery Charging in iOS is designed to extend battery lifespan by slowing charging above 80% until just before you typically unplug the phone. While good for battery health, it can slow down charging when quick full charges are needed.

In iOS 18, users can disable Optimized Battery Charging in Settings > Battery > Charging, which allows charging to proceed at maximum speed to the set limit without delay. Use this option when rapid charging is desired but re-enable it to preserve battery health over time.

Disable Clean Energy Charging

Clean Energy Charging schedules charging to make use of cleaner energy from the power grid, often slowing charging during peak hours. This feature can be turned off in Settings > Battery > Charging to allow charging to proceed immediately and at normal speeds regardless of the grid's carbon output status.

Disconnect Accessories While Charging

Using USB-C or Lightning accessories (headphones, adapters) during wireless charging may reduce charging power to 7.5W to meet regulatory standards. Disconnecting these accessories helps ensure wireless charging delivers its maximum wattage and speeds up charging times.

Regularly Check Battery Health

If charging remains slow despite implementing the above suggestions, battery health might be degraded. In Settings > Battery > Battery Health, check the maximum capacity percentage. Batteries below 80% capacity may charge slower and provide reduced battery life. Replacing the battery at an authorized service provider can restore optimal charging speed and battery performance.

Combining All Strategies

For the best charging speed improvements on iOS 18, combine the above strategies:
- Use a high-wattage USB-C or MagSafe certified charger and cable.
- Choose an appropriate charging limit (85%, 90%, or 95%) depending on usage.
- Turn off Optimized Battery Charging if you need a quick full charge.
- Implement automation to reduce power use during charging.
- Charge in a cool environment, disconnect unnecessary accessories.
- Minimize phone use during charging.
- Regularly monitor and maintain battery health.

By managing both software settings and hardware optimizations, iPhone users can significantly improve charging speed while balancing battery longevity with immediate power needs.