Your iPhone battery is draining faster than it charges because of background activity, heat, or a hardware problem with the charger or battery itself
When your iPhone loses charge while plugged in, the culprit is usually one of three things: apps running in the background and using more power than the charger supplies, the device overheating and throttling the charging speed, or a failing battery that no longer holds a charge properly. The charger itself can also be the problem — a damaged cable, a low-wattage adapter, or a port that does not make good contact will all result in slow or stalled charging.
The fix depends on which of these is happening. Some you can address in minutes. Others require a replacement part or a visit to Apple.
Key Takeaways
- Close all background apps and turn on Low Power Mode before charging to reduce the power drain while your charger works.
- Remove your phone from its case and let it cool down, since heat slows charging speed and can cause the battery to drain faster than it charges.
- Test with a different charger and cable — a damaged or underpowered adapter is one of the most common reasons charging fails.
- If the battery itself is worn out, only a replacement from Apple or an authorized repair shop will fix the problem permanently.
- Check the charging port for lint or debris and clean it gently with a dry cotton swab, since a poor connection prevents fast charging.
Close apps and enable Low Power Mode before charging
Apps running in the background consume power even while your phone is charging. If the apps are demanding enough, they can use more power than your charger supplies, causing the battery percentage to drop. The fastest way to stop this is to close all open apps and turn on Low Power Mode, which cuts background activity and reduces processor speed.
To enable Low Power Mode, open Settings, tap Battery, and toggle on Low Power Mode. Your phone will show a yellow battery icon at the top. Leave it on while charging and for a few hours afterward. If the battery stops draining once Low Power Mode is active, you have identified the problem — one or more apps are consuming too much power in the background.
You can also check which apps are using the most battery. Go to Settings, tap Battery, then Battery Usage. Apps listed at the top are the heaviest drains. If a single app is using more than 20 percent of your battery, consider uninstalling it or checking its settings to disable background refresh.
Remove the case and let your iPhone cool down
Heat is a silent battery killer. When your iPhone gets too warm, it automatically slows down the charging speed to protect the battery and other components. In extreme cases, the phone will stop charging altogether until it cools. If your phone feels warm to the touch while charging, remove the case when ready — cases trap heat and prevent air from reaching the phone's surface.
Set the phone on a cool, flat surface away from direct sunlight and away from heat sources like radiators or vents. Do not place it in a freezer or refrigerator, which can damage the battery and create condensation inside the device. Give it 15 to 20 minutes to cool. Once the phone feels cool, plug it back in and monitor whether the battery percentage rises.
If your phone regularly overheats while charging, check whether you are using it while it charges. Streaming video, playing games, or using GPS while plugged in generates heat faster than the charger can cool it. Avoid heavy use while charging, especially in warm environments.
Test with a different charger and cable
A damaged cable or an underpowered charger is one of the most common reasons an iPhone stops charging properly. Frayed cables, bent connectors, and worn charging ports all reduce the power flowing to your battery. If you have another charger and cable available — ideally one you know works with another device — plug your iPhone into it and watch whether the battery percentage rises.
Pay attention to the wattage of the charger. iPhones charge fastest with a 20-watt adapter or higher. If you are using an old 5-watt charger (the kind that came with older iPhones), it may supply less power than your phone draws, especially if apps are running. Check the wattage printed on the back of your charger. If it says 5W, 10W, or 12W, consider upgrading to a 20W or higher adapter.
Also test a different USB-C or Lightning cable, depending on your model. Cables wear out faster than adapters and are cheaper to replace. If the battery stops draining when you switch to a different cable, order a replacement from Apple or a certified third-party maker. Avoid counterfeit cables sold on marketplaces — they often fail quickly and can damage your phone.
Clean the charging port with a dry cotton swab
Lint, dust, and debris inside the charging port prevent the connector from making full contact with the cable. This reduces the power flowing into your phone and can cause slow or stalled charging. If you have not cleaned the port in months, this is likely the problem.
Power off your iPhone completely. Take a dry cotton swab and gently insert it into the charging port at the bottom of the phone. Twist it slowly to dislodge any debris. Do not use water, compressed air, or metal tools — water can damage the internal components, compressed air can push debris deeper, and metal can short the port. If lint is stuck, use a wooden toothpick instead of metal, and work very carefully.
Once the port looks clean, wait a few minutes for any remaining moisture to evaporate, then power the phone back on and try charging again. If the battery percentage rises steadily, the port was the problem. If it still drains, move on to the next step.
Check the battery health in Settings
Over time, iPhone batteries degrade and lose their ability to hold a charge. A battery that has gone through hundreds of charge cycles may no longer accept a full charge or may drain faster than it charges, even with a working charger. You can check your battery's health without opening the phone.
Go to Settings, tap Battery, then Battery Health & Charging. Look at the Maximum Capacity percentage. If it is 80 percent or higher, your battery is still in good condition. If it is below 80 percent, the battery has degraded and is likely the cause of your charging problem. The Condition field will also show whether the battery is Normal or Degraded.
If the battery health is below 80 percent or shows Degraded, the battery needs to be replaced. This is not something you can fix with settings or a different charger — only a replacement will solve the problem. Contact Apple Support or visit an Apple Store to arrange a battery replacement.
Force restart your iPhone if nothing else works
Sometimes a software glitch causes the charging system to malfunction even though the hardware is fine. A force restart clears temporary files and resets the charging logic without erasing your data.
The steps vary by model. On iPhone 8 and newer, quickly press and release the Volume Up button, then quickly press and release the Volume Down button, then press and hold the Side button until the power-off slider appears. Keep holding until the Apple logo shows up (about 10 seconds). On iPhone 7 and 7 Plus, hold the Volume Down button and the Side button together until the Apple logo appears.
Once your phone restarts, plug it in and check whether the battery percentage rises. If it does, the problem was a software glitch. If the battery still drains, the issue is hardware-related and requires a charger replacement or a visit to Apple.
When to contact Apple Support or visit an Apple Store
If you have tried all the steps above and your battery still drains while charging, the problem is likely a failing battery, a damaged charging port, or a defective charger that cannot be fixed with troubleshooting. At this point, contact Apple Support or make an appointment at an Apple Store Genius Bar.
Bring your phone, your charger, and your cable. The technician will test the charging system and battery health with Apple's diagnostic tools and can tell you exactly what needs to be replaced. Battery replacements typically cost between $50 and $100 depending on your model, and charger or port repairs may cost more. If your phone is still under warranty or covered by AppleCare+, the repair may be covered at no cost.
Do not attempt to replace the battery yourself unless you have experience with phone repair. Opening the phone voids the warranty and risks damaging other components.
Frequently Asked Questions
Why does my iPhone battery drain faster when I charge it in cold weather?
Cold slows down the chemical reactions inside the battery, which reduces the charging speed. Your phone may show a "temperature too low" message and stop charging until it warms up. Move to a warmer room and let the phone reach room temperature before plugging it in again. This is normal and does not mean the battery is damaged.
Can a third-party charger damage my iPhone battery?
A certified third-party charger with the correct wattage and connector type will not damage your battery. Uncertified chargers or chargers with the wrong wattage can overheat the battery or supply unstable power, which shortens its lifespan. Stick to chargers from Apple or brands certified by Apple, like Anker or Belkin.
Does leaving my iPhone plugged in overnight ruin the battery?
Modern iPhones have built-in protections that stop charging once the battery reaches 100 percent, so leaving it plugged in overnight does not cause when ready damage. However, keeping the battery at 100 percent for long periods does accelerate degradation over months and years. If you charge overnight regularly, unplug the phone once it reaches full charge.
What is the difference between a slow charge and a draining battery while charging?
A slow charge means the battery percentage rises, but very slowly — it might take several hours to reach 100 percent. A draining battery means the percentage actually drops while plugged in. Slow charging is usually caused by a low-wattage charger or background apps. A draining battery suggests a more serious problem like a failing battery or damaged charger.
Should I use my iPhone while it is charging if the battery is draining?
No. Using your phone while it charges generates heat and draws power away from the battery, making the problem worse. If your battery is draining while plugged in, turn off the phone or put it in Low Power Mode and let it charge without use for at least 30 minutes. This gives you a clear picture of whether the charger itself is the problem.