Wireless charging is usually slower than wired charging because it transfers power less efficiently, produces more heat, and often delivers less power than the charger's advertised maximum. Misalignment, thick phone cases, weak power adapters, background activity, and charging above 80% can slow it down further.
Qi2 25W products launched in 2025, but a higher-rated charger still cannot make a phone accept more power than its hardware and software allow.
At a Glance
| Cause | Effect on charging |
|---|---|
| Poor alignment | Reduces power transfer between the charging coils |
| Thick or metal case | Creates distance or interference |
| Heat | Causes the phone to reduce or pause charging |
| Low-power adapter | Limits power reaching the charging pad |
| Older Qi charger | May provide only 5W or 7.5W |
| Phone use while charging | Uses some or all incoming power |
| Battery above 80% | Charging slows during the final stage |
| Incompatible charger | Stops the phone from reaching its supported speed |
Why Wireless Charging Loses More Power
A wireless charger uses magnetic induction between a coil in the charging pad and a coil in the phone. The coils need to stay close together and properly aligned.
Some power is lost during that transfer, especially when the phone sits off-center or a thick case separates it from the pad. Qi2 uses magnetic alignment to keep the coils in position, which can improve charging efficiency and consistency.
With wired charging, power travels through a cable directly into the phone. That usually creates less heat and wastes less energy, so a USB-C connection can charge faster than a wireless pad with a similar advertised wattage.
The Charger's Wattage Is Not the Phone's Charging Speed
A wireless charger marked "15W" or "20W" does not mean every phone will charge at that rate. The phone, charging pad, power adapter, cable, charging standard, and software all affect the final speed.
Apple says an iPhone can take longer to charge with a wireless charger providing less than 10W, including many Qi-certified chargers. Apple recommends MagSafe or a Qi2-certified charger for faster wireless charging on supported iPhone models.
Google says some newer Pixel phones may charge at up to 5W with older Qi chargers. Qi2-compatible Pixel devices can charge faster when paired with the right certified charger and power adapter.
The phone sets the limit. A higher-wattage charging pad cannot force it to accept more power than it supports.
Heat Can Make Wireless Charging Slow
Wireless charging often creates more heat than wired charging because power passes through two coils instead of a cable. When the phone or battery gets too warm, the phone lowers the charging rate or pauses charging.
Apple says an iPhone may slow or pause charging in hot or cold conditions. The same protection applies to MagSafe and other wireless chargers. Google gives similar advice for Pixel phones, including removing the case, improving airflow, and keeping the phone out of direct sunlight.
Heat is more likely when you:
- Charge in direct sunlight or inside a hot car
- Use a thick case
- Play games or stream video while charging
- Use a pad with poor ventilation
- Place the phone on a warm surface
- Use mobile data in an area with a weak signal
Your Phone Case May Interfere With Charging
A case can slow wireless charging by increasing the distance between the phone and charging coil. Metal plates, magnetic ring holders, PopSockets, wallets, and some car-mount accessories can also interfere with the charging field.
Remove the case and test the phone again. If charging becomes faster or more stable, use a thinner case made for Qi or Qi2 charging. Google warns that thick or metallic cases, magnets, and ring holders can affect wireless charging.
The Phone May Be Poorly Aligned
Standard Qi chargers need reasonably accurate positioning. If the phone is slightly off-center, the pad may reduce power or repeatedly adjust the connection.
Try this:
- Place the charger on a stable, flat surface.
- Put the phone over the center of the pad.
- Remove metal objects and accessories from between the phone and charger.
- Avoid moving the phone while it charges.
- Use a magnetic Qi2 charger if both the phone and case support Qi2.
Qi2's magnetic attachment keeps the coils aligned, which can improve speed and consistency compared with a conventional Qi charger that is poorly positioned.
Charging Naturally Slows Above 80%
Phones do not charge at their fastest rate from 0% to 100%. They usually reduce power as the battery approaches full charge to limit heat and battery stress.
Apple describes faster charging up to approximately 80%, followed by slower charging during the final stage. Google also says adaptive charging can make charging above 80% appear slow because the phone manages when it reaches full charge.
If the phone charges quickly from 20% to 60% and slows near 80% or 90%, the charger may be working normally.
Phone Use Can Cancel Out the Charging Speed
The phone measures the power it receives after its own activity uses some of that power. A bright display, demanding game, active camera, video stream, or weak cellular signal can make charging appear much slower.
Apple identifies gaming, camera use, high-quality video streaming, and full screen brightness as activities that can reduce charging speed.
For the fastest result, turn off the screen, stop demanding apps, and avoid using the phone while it charges.
The Power Adapter or Cable May Be Too Weak
A wireless charging pad still needs a wired power connection. A low-power USB adapter, old USB-A adapter, laptop port, damaged cable, or multi-port adapter may stop the pad from reaching its rated output.
Connect the pad to a wall outlet with the adapter recommended by the phone or charging-pad manufacturer. Google says laptop USB-C ports and unsupported adapters can result in slower charging. Apple also warns that power output may drop when an adapter shares power across several ports.
How to Make Wireless Charging Faster
Use this troubleshooting order:
- Remove the phone case, especially if it is thick, metallic, magnetic, or includes a ring.
- Center the phone on the charging pad.
- Remove metal objects and accessories from the back of the phone.
- Use a wall outlet instead of a laptop or low-power USB port.
- Use the correct power adapter and cable for the charging pad.
- Keep the phone cool and out of direct sunlight.
- Stop games, video streaming, and other demanding apps.
- Check compatibility between the phone and the charger's standard, such as Qi, Qi2, or MagSafe.
- Test wired charging. If wired charging is also unusually slow, the problem may involve the adapter, cable, charging port, battery, or phone software.
- Check battery settings for messages such as "Slow Charger," "Charging on Hold," or adaptive charging notifications.
Is Wireless Charging Supposed to Be This Slow?
Yes, some slowdown is normal. Older Qi equipment, a low-power adapter, a thick case, poor alignment, and a warm phone can all reduce charging speed. Charging near 80% or higher is also slower by design.
If speed matters, use a cable. If convenience matters more, use a certified Qi2 or manufacturer-approved wireless charger that matches the phone's supported wattage. Wireless charging works well at a desk, overnight, or in a vehicle, but wired charging remains the better choice when the battery needs power quickly.