Apple has been innovating its smartphone technology for more than a decade now. Apart from its design and performance, the iPhone's battery life has always been a hot topic among gadget enthusiasts.
In iOS 13 and later systems, the iPhone has an Optimized Battery Charging feature that helps improve its battery health. Since the release of the iPhone 15 in 2023, Apple has added a new Charge Limit feature (80% Limit).
So, what's the difference between these two features, and which one should you use?
What Is Optimized Battery Charging?
Optimized Battery Charging is a feature that's available on iOS 13 and later. It utilizes machine learning algorithms to recognize your device's charging habits over time. It tracks when you charge your iPhone and how long it stays plugged in to optimize your battery charging patterns. By learning your daily routine, the feature can slow down battery aging by reducing the time your iPhone spends fully charged.
In the past, leaving your phone charging overnight will hurt your batteries. Instead of immediately charging to 100%, the optimized battery charging will juice up your phone to 80% of its full capacity initially. As morning approaches, the feature will then wait until closer to the time you wake up before topping off your phone 100%.
The purpose of this feature is to prevent unnecessary wear and tear on your battery cells. Frequent exposure to high temperatures and being fully charged can cause permanent damage to your battery, ultimately leading to a shorter battery life. By monitoring your charging habits and adjusting the charging rate, your iPhone's battery health can be improved.
What Is iPhone’s 80% Limit? Is It Good for the Battery?
In addition to Optimized Battery Charging, the iPhone 15 introduced a new charging feature called “80% Limit” that prevents your device from charging past 80%. The idea was to reduce battery wear and extend lifespan.
According to the "40-80 Rule", lithium-ion batteries, like the ones inside iPhones, work best when they are between 40% and 80% of their capacity. When they are too full or too low, they experience more wear and lose their ability to hold a charge over time.
However, many users complained 80% wasn’t enough to get through a full day. Apple listened to the feedback. In iOS 18, they updated the feature, giving users more options. Now, you can choose to stop charging at 80%, 85%, 90%, 95%, or 100%.
So why would you want to limit your charge?
By limiting your iPhone's charge percentage, you can protect your battery from overheating and overcharging, and reduce the number of charged cycles that the battery goes through.
So, what is the battery's charge cycle? Each complete charge cycle is regarded as a one-cycle count. As the battery undergoes more charge cycles, the battery's chemical reaction experiences wear and tear, causing a gradual reduction in its overall capacity and performance. According to Apple, a battery under normal use retains up to 80% of its original capacity after 500 complete cycle charges.
To put it short, the more cycles your battery completes, the shorter life it becomes. In this case, the Charge Limit is just the right feature to minimize the impact on your battery.
Give Up Battery Capacity? No Way!
Though using the charge limit has a significant benefit, it means you have to sacrifice a certain percentage of battery capacity in daily use, probably resulting in a lack of power supply if you are a heavy phone user. So, it seems to be a dilemma between a longer battery life and normal daily battery use.
Fortunately, using charging solutions that can supply timely power for your device is an effective way to have this issue handled.
The solution is to use a portable MagSafe power bank. PITAKA's Aramid Fiber Magnetic Power Bank, with 5000mAh battery capacity, gives you peace of mind charging your device anywhere, anytime, providing more power and longer life. It's MagSafe compatible, Qi2 certified, and supports up to 15W fast wireless charging. Ultra-light and slim, the power bank won't add bulk when attached to your phone. Plus, the aramid fiber material offers both a premium tactile feel and an elegant aesthetic, making it a perfect combination of functionality and style.

If you prefer higher efficiency from wall chargers, PITAKA's USB C GaN charger will be highly recommended because of its 30W output that fast charges your iPhone. It is compatible with all devices with a USB-C port. Besides, its compact size makes it incredibly portable, so you can always have it handy when you need a quick boost. No more worry about your battery hitting low even if you're traveling.
How to Set a Charge Limit on Your iPhone?
With the availability of charging solutions, you can embrace a healthier battery performance by setting a charge limit.
If you have an iPhone 15 and haven’t updated to iOS 18
1. Open the Settings App on your iPhone.
2. Scroll downwards and select the Battery option.
3. Tap on Battery Health & Charging.
4. Select Charging Optimization, and you'll be presented with three options: Optimized Battery Charging, 80% Limit, or None.
Optimized Battery Charging: Your iPhone will charge according to your charging habits.
80% Limit: Your iPhone will stop charging when the battery reaches 80%.
None: Your iPhone will charge fully with no restrictions.
5. Choose "80% Limit" to enable the feature.
Apart from charging settings, you can also check the Battery Cycle Count on the iPhone 15 to have better knowledge about your battery consumption and health.
1. Open the Settings app.
2. Tap General and then select About.
3. Scroll downwards to the Battery section and you'll see the battery's Manufacture Date, First Use, and Cycle Count.
If you have an iPhone 16, or iPhone 15 with the latest iOS 18:
1. Open Settings on your iPhone.
2. Scroll down and tap Battery.
3. Select Charging.

4. Turn off Optimized Battery Charging (if it’s on).
5. Choose a charge limit: 80%, 85%, 90%, 95%, or 100%.

To check your battery health, follow these steps:
1. Open the Settings App on your iPhone.
2. Scroll downwards and select the Battery option.
3. Tap Battery Health, and you'll see Maximum Capacity, Cycle Count, Manufacture Date, and First Use.

Conclusion
Battery life is always one of the topics most concerned and shortens over time. The introduction of the charge limit helps you manage your phone charging more conveniently. It is an effective way to prevent unnecessary wear and tear on your battery cells, thus prolonging the overall battery life of your iPhone.
FAQs
Q1: What is the difference between Optimized Battery Charging and Charge Limit?
A1: Optimized Battery Charging works by learning your charging habits. It stops charging when it reaches 80%, and then completes the rest 20% before you need it.
Charge Limit, on the other hand, is a way to restrict charging to a maximum level less than 100%. It reduces the possibilities of overheating and overcharging, further improving your battery health.
Q2: Can I disable the Charge Limit if I want full capacity?
A2: Of course you can. You can go to Settings App > Battery > Charging, and enable Optimized Battery Charging.