iPhone charging time depends on your charger, cable, and battery size
A new iPhone with a completely empty battery takes roughly 30 minutes to reach 50% charge and 2 to 3 hours to reach 100% when using Apple's standard charger. But that number shifts based on three things: which iPhone model you own, what charger you plug it into, and what the phone is doing while it charges. An older iPhone 12 charges slower than a newer iPhone 15. A 5-watt charger takes twice as long as a 20-watt charger. And if you are using your phone while it charges, the battery fills more slowly.
The real-world charging time you experience also depends on the battery's current state. Phones charge fastest in the middle of their cycle — between 20% and 80%. The last 20% to reach 100% intentionally slows down to protect battery health, a feature Apple built in starting with iPhone 13. If your phone is hot, it will also throttle charging speed automatically to prevent damage.
Key Takeaways
- Standard iPhone charging with Apple's included charger takes 2 to 3 hours from empty to full, but the last 20% charges much slower to protect battery lifespan.
- A 20-watt charger reaches 50% in about 30 minutes, while older 5-watt chargers take roughly an hour to hit that mark.
- Charging speed slows if your phone is hot, if you are using it while plugged in, or if the cable or charger is damaged.
- Optimized Battery Charging, turned on by default, learns your charging habits and holds the battery at 80% until you need it, which extends overall battery lifespan but means your phone may not reach 100% until shortly before you unplug it.
How charger wattage affects charging speed
The charger's wattage is the single biggest factor you control. Apple's standard charger for most current iPhones is 20 watts. Older iPhones came with 5-watt chargers, which are still functional but charge roughly four times slower. A 20-watt charger will reach 50% in about 30 minutes on a current iPhone, while a 5-watt charger takes closer to an hour.
Higher-wattage chargers exist — 30-watt, 35-watt, and even 65-watt options — but iPhones have a built-in limit on how fast they will accept power. An iPhone 15 will accept up to 20 watts of wired charging power, so plugging it into a 65-watt charger does not make it charge faster. Older models like the iPhone 12 accept even less. Check Apple's technical specifications for your specific model to see its maximum charging speed.
Wireless charging is slower across the board. Standard wireless chargers deliver 5 to 7.5 watts, which means a full charge takes 3 to 4 hours. MagSafe wireless chargers deliver up to 15 watts on newer iPhones but still take longer than wired charging.
Why the last 20% takes so much longer
If you have noticed your iPhone crawling toward 100% in the final stretch, that is intentional. Starting with iPhone 13, Apple added a feature that slows charging dramatically once the battery reaches 80%. This slowdown protects the battery's long-term health by reducing stress during the final charge cycle.
Lithium batteries degrade faster when held at 100% charge, especially if they stay there for hours. By charging to 80% at full speed and then creeping the last 20% slowly, Apple extends how many years your battery will hold a useful charge. The tradeoff is that reaching 100% can take an extra 30 to 60 minutes beyond what the first 80% took.
You can turn this feature off in Settings under Battery, but doing so will shorten your battery's lifespan over time. Most people find the tradeoff worth it — a battery that lasts four years at 80% capacity is more useful than one that reaches 100% faster but degrades to 80% capacity in two years.
Optimized Battery Charging and when your phone stops at 80%
Optimized Battery Charging is turned on by default on all current iPhones. It learns when you typically charge your phone overnight and holds the battery at 80% until shortly before you wake up, then finishes the last 20% in the final hour. This means if you plug in at 10 p.m. and wake at 7 a.m., your phone will sit at 80% from 10 p.m. to 6 a.m., then charge to 100% between 6 and 7 a.m.
The feature works only for overnight charging. If you charge during the day, your phone will charge to 100% normally. Optimized Battery Charging is designed to reduce the total time your battery spends at maximum charge, which is when degradation happens fastest.
If Optimized Battery Charging is preventing you from reaching 100% when you need it, you can disable it temporarily by opening Settings, going to Battery, then Battery Health, and turning off Optimized Battery Charging. The setting will turn back on automatically the next day. You can also disable it permanently, but Apple recommends leaving it on for the longest battery lifespan.
What slows down charging mid-cycle
Even before reaching 80%, several things can cut charging speed in half or more. If your iPhone is hot — whether from use, sunlight, or a warm environment — it will throttle charging automatically. This is a safety feature. Charging a hot battery can damage it permanently, so the phone prioritizes safety over speed.
Using your phone while it charges also slows the process. Streaming video, gaming, or running apps draws power at the same time the charger is trying to add power, so the net gain is slower. Closing apps and letting the phone sit idle while charging is the fastest route.
A damaged cable or charger will also reduce speed. If the connector is bent, corroded, or loose, the phone may not recognize the charger as capable of delivering full power and will charge at a lower rate. Try a different cable or charger to see if speed improves. If it does, the original cable or charger is likely damaged.
Charging times for different iPhone models
| iPhone Model | Battery Capacity | Time to 50% (20W charger) | Time to 100% (20W charger) |
|---|---|---|---|
| iPhone 15 | 3,349 mAh | ~30 minutes | ~2 hours |
| iPhone 15 Pro Max | 4,685 mAh | ~35 minutes | ~2.5 hours |
| iPhone 14 | 3,279 mAh | ~30 minutes | ~2 hours |
| iPhone 13 | 3,240 mAh | ~30 minutes | ~2 hours |
| iPhone 12 | 2,815 mAh | ~28 minutes | ~1.5 hours |
Larger phones with bigger batteries naturally take longer to charge fully. An iPhone 15 Pro Max has a battery roughly 40% larger than a standard iPhone 15, so it takes proportionally longer. However, the difference between models is smaller than the difference between chargers — upgrading from a 5-watt to a 20-watt charger saves more time than upgrading from an iPhone 14 to an iPhone 15.
Fast charging and when it matters
If you regularly find yourself with a dead phone and limited time, a 20-watt charger is the practical minimum. It reaches 50% in 30 minutes, which is enough for most people to get through a day. If you need faster charging, look for a 30-watt or higher charger from Apple or a certified third-party maker, but remember that iPhones have a maximum charging speed built in — you cannot make them charge faster than their design allows.
Wired charging is always faster than wireless, so if speed matters, use a cable. Wireless charging is convenient for overnight charging or when you are at a desk, but it is not the right choice when you need a quick top-up.
Battery health also affects how fast your phone charges. An old battery that has degraded to 80% capacity may charge slightly slower than a new one, though the difference is usually small. If your iPhone is several years old and charging feels noticeably slower than it used to, a battery replacement from Apple or an authorized repair shop can restore charging speed.
Frequently Asked Questions
Why does my iPhone charge faster to 50% than from 50% to 100%?
Batteries charge fastest in the middle of their cycle and slowest at the extremes. Your phone intentionally slows charging above 80% to protect battery health. Between 50% and 80%, charging is still fast, but the final 20% creeps along to reduce stress on the battery.
Does leaving my iPhone plugged in overnight damage the battery?
No, not with Optimized Battery Charging turned on. The feature holds your phone at 80% for most of the night and finishes charging shortly before you wake up, so the battery does not spend hours at 100%. Without this feature, leaving it plugged in every night will degrade the battery faster over time.
Can I use my iPhone while it charges?
Yes, but it will charge more slowly. The phone is drawing power to run apps at the same time the charger is adding power, so the net gain is reduced. For the fastest charge, close apps and let the phone sit idle.
Is a third-party charger safe to use?
Chargers certified by Apple or that meet USB-C Power Delivery standards are safe. Uncertified chargers from unknown makers can damage your phone or battery. Check the packaging for certification marks or buy from established brands.
What should I do if my iPhone is charging very slowly?
Try a different cable and charger first — a damaged cable is the most common cause. If speed improves, replace the original cable. If it does not improve, restart your phone, check that Optimized Battery Charging is not holding it at 80%, and make sure the phone is not hot. If charging is still slow after these steps, the battery may be degraded and worth replacing.