iPhone Not Charging Past 80%? Here’s Why and What to Do

You plug your iPhone in before bed, certain it’ll hit 100% by morning. But when you wake up, it’s still stuck at 80%. Confusing, right?

Don’t stress. If your iPhone won’t charge past 80%, that doesn’t always mean something’s broken. Most of the time, your phone’s just protecting itself from heat or battery wear. Still, there are moments when it hints at a real issue.

Here, you’ll find out what causes your iPhone not charging past 80%, how to fix it fast, and how to keep your battery in good shape for longer.

 

 

Why Is My iPhone Not Charging Past 80% and How to Fix It?

If your iPhone won’t charge past 80%, it’s easy to assume something’s wrong. But most of the time, your phone is protecting the battery or following a setting you can change. Below are the most common reasons and quick fixes for each.

1. Optimised Battery Charging is pausing at 80%

Your iPhone includes a smart feature called Optimised Battery Charging, designed to make your battery last longer. Lithium-ion batteries age faster when they spend too much time at 100%. To prevent that, your phone learns your daily routine and slows charging once it reaches 80%.

It uses on-device machine learning to predict when you’ll normally unplug, for example, around the time you wake up or leave for work. Instead of staying at 100% all night, the iPhone holds the charge at 80% and quietly finishes the last 20% just before you need it. You will notice a small message on your lock screen:

“Optimised Battery Charging. Scheduled to finish charging by [time].”

This is your phone protecting itself. Over time, that small adjustment can significantly reduce battery wear and keep performance steady for years.

How to fix it (or control it)

[if !supportLists]· [endif]If you need a full charge now, tap and hold the lock-screen message and choose Charge Now.

[if !supportLists]· [endif]You can also turn the feature off by going to Settings ▸ Battery ▸ Battery Health & Charging, then switching off Optimised Battery Charging.

[if !supportLists]· [endif]On iPhone 15 models and newer, go to Settings ▸ Battery ▸ Charging and toggle off Optimised Battery Charging.

[if !supportLists]· [endif]If you’ve recently changed your routine, say, new work hours or travel, the feature may seem inconsistent. Give it a few days to relearn your habits.

[if !supportLists]· [endif]Make sure Location Services and Significant Locations are on (under Privacy & Security ▸ Location Services) so your iPhone can better predict when and where you usually charge.

 

 

2. An 80% Charge Limit is turned on (iPhone 15 and later)

Is your iPhone 15 Pro not charging past 80%? It might be a Charge Limit.

On iPhone 15 models and newer, you can set a Charge Limit (e.g., 80–100% in 5% steps) to slow battery wear. If you choose 80%, your iPhone will intentionally stop around that level and only top up if it dips several points while still plugged in.

How to fix it

[if !supportLists]· [endif]Go to Settings ▸ Battery ▸ Charging and raise or turn off the Charge Limit.

[if !supportLists]· [endif]If you need a full charge just for today, tap Allow Until Tomorrow.

[if !supportLists]· [endif]To remove the limit entirely, tap Set Limit to 100%.

3. Your iPhone is too warm (or too cold), so charging is on hold

If you’re wondering, “Why won’t my iPhone charge past 80%?” check whether your device is too hot or too cold.

iOS pauses charging when the battery is outside a safe temperature range (0º and 35ºC). You may see “Charging On Hold. Charging will resume when iPhone returns to normal temperature.” It’s a safety step to protect the battery.

How to fix it

[if !supportLists]· [endif]Move the phone somewhere cooler or warmer, away from direct sunlight, radiators, car dashboards, or chilly windowsills.

[if !supportLists]· [endif]Remove bulky cases while charging so heat can escape.

[if !supportLists]· [endif]If you’re wireless charging and the phone feels warm, switch to a cable until it cools down.

[if !supportLists]· [endif]Charging will resume automatically once the temperature’s right.

4. Charger, cable, or port problems

A worn cable, dusty charging port, or low-quality third-party adapter can interrupt charging or make it stall, sometimes right around 80%. You might also see messages like “Accessory not supported.”

How to fix it

[if !supportLists]· [endif]Try a known-good, certified cable/adapter and a different wall outlet. (Look for the MFi certification for Lightning accessories.)

[if !supportLists]· [endif]Check and clean the charging port carefully if you suspect lint or debris. Use a soft brush or wooden toothpick; avoid metal tools.

[if !supportLists]· [endif]Still seeing alerts? Restart your iPhone or update iOS, then test again.

[if !supportLists]· [endif]If problems persist, book Apple Support.

Realised your charger might be the problem? It happens. Over time, adapters lose efficiency or stop delivering a steady flow of power. Some cheaper or older USB chargers simply can’t meet the precise voltage newer iPhones need.

When you replace yours, look for a certified USB-C Power Delivery (PD) charger from a trusted brand. That’s the standard Apple now uses for safe, fast charging.

Here are two reliable chargers from Anker, both fast, safe, and built to last.

Need a small but powerful charger? The Anker Nano Charger (45W) is a single-port GaN adapter that delivers fast, efficient USB-C PD charging without overheating your device. With a steady 45W output, it can take an iPhone 17 Pro Max from 0% to 50% in about 20 minutes, and it’s strong enough to charge iPads or smaller laptops, too.

If you’ve got friends or family on Samsung, it’s just as capable. Thanks to PPS support, it fully powers Samsung Super Fast Charging 2.0 (45W) on the Galaxy S25+ and Ultra models.

The plug folds, and the body is genuinely compact (about 49 × 49 × 34.1 mm, ~100 g), so it slips in a pocket or laptop sleeve. Anker’s ActiveShield 3.0 monitors temperature around 6 million times a day to keep heat in check, which helps protect your battery during longer top-ups. The housing also uses PCR (recycled) materials to cut virgin plastic.

 

 

If you want one desktop charger for everything, this Anker Prime Charger (250W) is the tidy, do-it-all hub. You get four USB-C and two USB-A ports with up to 250W total output, enough to power a laptop, iPhone, tablet, and earbuds all at once. The USB-C1 port goes up to 140W, easily handling a 16” MacBook Pro or similar high-demand device.

There’s a small display on the front showing real-time power use, so you can see what’s charging where. The charger automatically adjusts output across ports to give each device what it needs, which means fewer slow-downs and less heat.

You can set up AI or port priority charging modes through the Anker app and swap them easily with the smart control knob.

 

 

5. Battery health is degraded (time for a check)

All lithium-ion batteries age. As capacity falls, the phone may heat more under charge and pause more often, or you might see a battery service message in Battery Health. While this doesn’t hard-cap you at 80%, it can make hitting 100% less consistent.

Open Settings ▸ Battery ▸ Battery Health. If you see a service recommendation, arrange a battery replacement with Apple or an authorised provider.

Preventive Tips & Best Practices for Battery Health

Good charging habits keep your iPhone battery healthy and consistent. Here’s how to look after it day to day.

Avoid extreme temperatures

Batteries dislike heat and cold. Both can slow charging or cause damage.

[if !supportLists]· [endif]Keep your phone out of direct sunlight, cars on hot days, or near heaters.

[if !supportLists]· [endif]Always place your iPhone on a hard and cool surface during charging. Don’t cover it with cushions or blankets.

[if !supportLists]· [endif]In winter, avoid leaving it out in the cold for long periods.

[if !supportLists]· [endif]If it feels hot while charging, move it to a cooler spot and remove the case.

Don’t chase 100% every time

Charging to full every night isn’t necessary. Your battery lasts longer when it stays between 20% and 80%.

[if !supportLists]· [endif]Leave Optimised Battery Charging or Charge Limit on to handle this automatically.

[if !supportLists]· [endif]Full charges aren’t harmful occasionally, but keeping the battery maxed out for hours adds stress over time.

Use certified chargers and cables

Low-quality chargers can cause heat or power issues. Stick with Apple-certified (MFi) gear or trusted brands like Anker. Avoid cheap, unverified cables.

Keep iOS updated

Each iOS update fine-tunes battery management and charging behaviour. Go to Settings ▸ General ▸ Software Update and install updates regularly.

Limit background drain

Apps running in the background or pushing constant notifications can drain your battery faster than you think.

[if !supportLists]· [endif]Review which apps can refresh in the background under Settings ▸ General ▸ Background App Refresh.

[if !supportLists]· [endif]Turn off unnecessary location tracking under Privacy & Security ▸ Location Services.

[if !supportLists]· [endif]If your phone runs warm often, check for power-hungry apps or poor network coverage. Both can make it work harder.

Conclusion

Your iPhone not charging past 80% is usually not a fault. It’s your device protecting its battery. Features like Optimised Battery Charging and temperature safeguards are built to help your phone last longer. Still, it’s worth knowing when to step in, whether that means cooling your phone, swapping a charger, or checking your settings. With a few smart habits and the right accessories, you can keep your iPhone charging smoothly and your battery strong for years to come.

FAQs

Why does my iPhone stop charging at 80%?

Your iPhone may pause at 80% to look after the battery. The Optimised Battery Charging feature learns your routine and delays charging past 80% to slow down wear over time. If you have an iPhone 15 or newer, a Charge Limit setting might also be keeping it there. And if your phone gets too warm, iOS may stop charging until it cools down. All of this is completely normal and helps your battery last longer.

How can I make my iPhone charge more than 80%?

There are a few simple fixes. If Optimised Battery Charging is active, you’ll see a message on the Lock Screen. Press and hold it, then tap “Charge Now”. On iPhone 15 or later, open Settings > Battery > Charging and move the Charge Limit to 100%, or tap Allow Until Tomorrow. If your phone feels warm, let it cool down first; charging will continue automatically once the temperature is safe again.

How to reset iPhone battery to 100%?

You can’t fully reset battery health, but you can calibrate it to make the charge reading more accurate. First, use your iPhone until it powers off by itself. Leave it off for about an hour, then charge it (while still off) to 100%. Keep it plugged in for another hour after it’s full, then restart the phone. If it often stops at 80%, turn off Optimised Battery Charging in Settings > Battery > Battery Health & Charging, or on iPhone 15 and later, set the Charge Limit to 100%. This helps ensure a full charge.

How to change iPhone battery from 80 to 100?

If you’re using an iPhone 15 or later, open Settings > Battery > Charging and slide the Charge Limit up to 100%. You can also tap Charge to 100% or Allow Until Tomorrow for a one-off boost. On older iPhones, there’s no limit setting, so if charging stops at 80%, it’s probably Optimised Battery Charging. Just hold the Lock Screen alert and choose Charge Now to continue.