Slow charging usually means either the charger itself is weak, the cable is damaged, or something is running hard in the background while you charge
A phone that takes hours to reach full battery is almost always fixable without replacing the device. The culprit is usually one of three things: the charger or cable is not delivering full power, the phone is too hot, or apps and processes are draining power faster than the charger can replace it. Start by testing with a different charger and cable — many people discover their original charger was the problem all along.
The speed at which your phone charges depends on how much electrical current the charger can push into the battery. A charger rated for 5 watts will charge much slower than one rated for 20 watts or 30 watts. If you have been using the same charger for years, or if it came with a budget phone, it may straightforward be underpowered for your current device.
Key Takeaways
- Test with a different charger and cable first — a damaged or low-power charger is the most common reason for slow charging.
- Check your phone's settings to see what wattage your charger supports, then compare it to what your phone can actually accept.
- Close apps running in the background, turn off location services, and lower screen brightness while charging to reduce power drain.
- If your phone gets hot while charging, stop and let it cool — heat slows charging and damages the battery over time.
- Wireless chargers are always slower than wired ones; if speed matters, use a wired charger instead.
Check whether your charger matches your phone's power rating
Every phone has a maximum charging speed it can accept, measured in watts. An iPhone 15 can accept up to 20 watts through a wired charger. A Samsung Galaxy S24 can accept up to 25 watts. If you are using a 5-watt charger — the kind that came with older iPhones or budget Android phones — your phone will charge at that slower speed no matter how new the device is.
To find your phone's maximum charging speed, search the manufacturer's website for your exact model number. Look for "charging specifications" or "fast charging" in the technical details. Then look at your charger: the wattage is usually printed on the brick itself, or on the label if it is a wall adapter. If your charger is rated lower than your phone's maximum, upgrading to a charger that matches your phone's spec will make a noticeable difference.
Keep in mind that using a charger rated higher than your phone's maximum will not damage it — your phone will straightforward charge at its own maximum speed and ignore the extra power. A 30-watt charger will not harm a phone that only accepts 20 watts.
Inspect the cable for damage and test a different one
A frayed, bent, or partially broken cable can reduce charging speed dramatically even if the charger itself is fine. The cable carries the electrical current from the wall to your phone, and any damage along the way creates resistance that slows the flow. Bend your cable gently along its entire length and look for cracks in the rubber coating, especially near the connectors where cables bend most often.
The easiest test is to borrow a different cable and try charging with it. If your phone charges noticeably faster with a different cable, your original cable is the problem. Replace it with a cable rated for your phone's charging speed — look for "fast charging" or the wattage specification on the package. Cheap third-party cables often cannot handle high-wattage charging even if they physically fit your phone.
Close apps and reduce what your phone is doing while it charges
Every app running in the background, every video playing, every location service tracking your position — all of these drain battery power while your charger is trying to fill it. If your phone is working hard, the charger has to overcome that drain before it can actually add charge to the battery. The result is slower net charging speed.
Before plugging in, close apps you are not using. On iPhone, swipe up from the bottom and close apps in the app switcher. On Android, open Settings, go to Apps, and force-stop any apps you do not need running. Turn off location services, Bluetooth, and Wi-Fi if you do not need them. Lower your screen brightness or turn the screen off entirely — the display is one of the biggest power drains on any phone.
If you are downloading files, streaming video, or playing games while charging, stop. These activities pull power faster than most chargers can deliver it, which means your battery percentage may stay flat or even drop while the charger is plugged in.
Let your phone cool down if it is hot while charging
Heat is the enemy of both charging speed and battery health. When a phone gets too warm, it automatically slows down charging to protect the battery from damage. If your phone feels hot to the touch while plugged in, unplug it and let it cool for 10 to 15 minutes before charging again.
Heat during charging usually comes from one of two sources: the charger itself is faulty and generating excess heat, or the phone is working too hard (running apps, processing data) while charging. If the charger itself is hot, stop using it — a faulty charger can damage the battery or create a safety risk. If the phone is hot but the charger feels normal, close your apps and reduce background activity as described above.
Avoid charging in direct sunlight or in a hot car. If you need to charge quickly, do it in a cool room with the phone in airplane mode and the screen off. This removes almost all power drain and lets the charger work at full speed.
Understand why wireless charging is always slower
Wireless chargers are convenient but inherently slower than wired ones. A typical wireless charger delivers 5 to 15 watts, while a modern wired fast charger delivers 20 to 65 watts depending on the phone. The difference is physics: wireless charging has to transmit power through the air gap between the charger and the phone's coil, which loses efficiency in the process.
If you need your phone charged quickly, use a wired charger. Wireless charging is best for overnight charging or for situations where you want to set the phone down and forget about it. If your phone supports fast wired charging, that will always be faster than any wireless option available today.
Check your battery health if charging is slow even with a good charger
If you have tested with a new charger and cable, closed your apps, and your phone still charges slowly, the battery itself may be degraded. Batteries lose capacity over time — after two or three years of daily use, a battery may only hold 80 percent of its original charge, and it may charge more slowly as well.
On iPhone, go to Settings, Battery, Battery Health and Charging. If the Maximum Capacity is below 80 percent, your battery is aging and will charge more slowly than it did when new. On Android, the process varies by manufacturer, but many phones show battery health in Settings, Device Care, or Battery. If your battery health is poor and your phone is out of warranty, you can have the battery replaced by the manufacturer or by a repair shop, which is usually cheaper than buying a new phone.
Frequently Asked Questions
Why does my phone charge faster when it is off?
When your phone is off, it is not running any apps, refreshing email, or updating location. The charger does not have to overcome any power drain, so all of its output goes directly into the battery. Turning the phone off or putting it in airplane mode before charging will speed up the process noticeably.
Does using my phone while charging slow it down?
Yes. Every app you use, every video you watch, and every notification that arrives pulls power from the battery while the charger is trying to fill it. The charger has to overcome that drain first. If you want fast charging, put the phone down and leave it alone.
Can a bad charger damage my phone?
A charger rated for your phone's voltage will not damage it, even if it is low-wattage — it will just charge slowly. However, a charger that is physically damaged, extremely hot, or from an unreliable brand can pose a safety risk. If your charger gets hot or smells odd, stop using it.
Is it bad to charge my phone overnight?
Modern phones stop charging once they reach 100 percent and switch to a trickle charge to maintain the level. This is safe for occasional overnight charging. However, keeping a battery at 100 percent constantly does degrade it slightly over time. If you charge overnight regularly, consider unplugging once it reaches full charge.
Why is my phone slower to charge in cold weather?
Cold temperatures slow the chemical reactions inside a battery, which reduces how fast it can accept a charge. This is temporary — once the phone warms up, charging speed returns to normal. Never try to heat a cold phone with direct heat; just let it warm naturally at room temperature.