iPhone Battery & Charging 101: The Ultimate Guide to Charging iPhones and Maximizing Battery Life

Proper battery maintenance is essential for prolonging the lifespan and performance of your iPhone. Did you know that 52% of iPhone users report that their phone's battery drains very quickly? So, if your iPhone is dying faster than your patience with slow Wi-Fi, you’re not alone. The need to understand how to properly charge and maintain your iPhone's battery is quite real. 

In this guide, we will help you understand iPhone batteries, bust typical charging myths, discuss best practices, and reveal all the secrets to maximize your iPhone’s battery life.

At Reboxed, we not only offer top-quality refurbished iPhones but also ensure that each device comes with a battery in excellent condition. This commitment to quality and sustainability helps our customers get the most out of their iPhone while contributing to a greener planet. That being said, let’s dive in!

Understanding iPhone Batteries

Types of Batteries

Gone are the days of NiMH batteries and "memory effect" worries. iPhones use Lithium-ion (Li-ion) batteries, which are preferred for their high energy density and ability to recharge quickly. Li-ion batteries are lightweight, making them ideal for mobile devices. 

Battery Capacity

Battery capacity is measured in milliampere-hours (mAh). This measurement indicates how much energy the battery can store. A higher mAh means a longer battery life between charges, translating to more hours of use for activities like browsing, streaming, and gaming. Looking for the best iPhone model that can last the longest? Head here to find the best iPhones ranked as per their battery life.

Battery Lifespan

According to Apple, the typical lifespan of an iPhone battery is about 300-500 full charge cycles (depending on the model), after which it retains approximately 80% of its original capacity. A charge cycle is defined as using 100% of the battery's capacity, whether it's from a full 0-100% charge or multiple partial charges that add up to 100%. 

Things you need to keep in mind a.k.a. the factors that affect battery lifespan include: 

  • Temperature exposure: Extreme temperatures can degrade battery health
  • Charging habits: Too many frequent full discharges and overcharging can shorten battery lifespan
  • Intensity of daily usage: High-demand activities drain the battery faster and contribute to more charge cycles

As a rule of thumb, keeping your battery between 20-80% charged can help prolong its life. Understanding charge cycles is important because each cycle incrementally degrades battery capacity, impacting overall battery health and device performance.

Busting iPhone Battery and Charging Myths

Many myths surround iPhone battery charging, leading to confusion and improper care. Let’s debunk some common misconceptions to help you actually maintain your iPhone battery better.

Myth 1: Charging iPhones Overnight Damages the Battery

  • Truth: Modern iPhones have built-in mechanisms to stop charging when the battery is full, preventing overcharging. The "charger" is built-in: the wall plug and cable simply deliver the juice. The real brains of the operation are inside your iPhone, safeguarding your precious battery. So, go crazy. Sleep with your iPhone on charge, your battery won’t mind. 

Myth 2: You Should Let Your Battery Drain Completely Before Recharging

  • Truth: Lithium batteries don't have a "memory effect". They perform best when kept partially charged. So, charge your iPhone however you like, as often as you like, without worry. Maintain 20%-80% when possible and you’re good! Regularly draining them completely (deep discharges) can actually reduce their lifespan. If your phone dies completely, charge it up as soon as possible. Leaving it drained for extended periods can stress the battery.

Myth 3: Using Non-Apple Chargers Will Damage Your Battery

  • Truth: While some non-certified chargers can be harmful, any high-quality certified charger is safe and effective. For the best outcomes, stick with high-quality power sources and cables certified by Apple's "Made for iPhone" (MFi) program.

Myth 4: Closing Background Apps Saves Battery

  • Truth: Background apps don’t significantly impact battery life. Instead, it’s app refreshes and notifications that matter more.

Myth 5: Fast Charging Harms the Battery

  • Truth: Fast charging is designed to be safe for iPhones. While it may cause minimal additional wear, it’s not significant enough to worry about.

Myth 6: Wi-Fi and Bluetooth Should Always Be Turned Off to Save Battery

  • Truth: Modern iPhones are optimised to manage these connections efficiently, and the battery savings are minimal.

Best Practices for Charging iPhones

Optimal Charging Range

Full charge cycles (0% to 100%) take a toll. To prolong your iPhone’s battery lifespan, it’s best to keep the charge between 20-80%. This range minimizes the stress on the battery, reducing wear and tear over time. Avoid letting the battery completely drain or fully charge regularly, as this can accelerate battery degradation.

Avoid Extreme Temperatures

Temperature extremes can significantly impact your iPhone’s battery health. High temperatures can cause the battery to degrade faster, while low temperatures can temporarily reduce battery performance. Aim to keep your iPhone in environments between 0°C and 35°C (32°F to 95°F) for optimal battery health.

Use Apple-Certified Accessories When Possible

Using Apple-certified chargers and cables ensures that your iPhone charges safely and efficiently. Some non-certified accessories can cause damage or fail to provide the necessary power, potentially harming the battery. Always look for the MFi (Made for iPhone) certification when purchasing charging accessories.

By following these best practices, you can maintain your iPhone’s battery health and ensure it performs optimally throughout its lifespan.

Top Tips on How to Maximize Your iPhone's Battery Life

  1. Keep Your iOS Updated

Regular software updates from Apple often include battery optimisation improvements. Keeping your iPhone updated ensures you benefit from the latest features that can improve battery performance​.

  1. Monitor Battery Health Settings

To check and manage your battery health, go to Settings > Battery > Battery Health. Here you can see the battery's maximum capacity and turn on Optimized Battery Charging (iOs 13 and above) to slow down battery aging by learning your charging routine and preventing full charges until necessary​​.

  1. Disable Background App Refresh

Background app activities can drain your battery. Go to Settings > General > Background App Refresh and turn off the feature entirely or limit it to Wi-Fi only. This reduces the energy consumption of apps running in the background​​.

  1. Enable Low Power Mode

Low Power Mode is a quick way to extend battery life by reducing background activity, disabling mail fetch, and lowering display brightness. Activate it through Settings > Battery or add it to the Control Center for easy access​.

  1. Adjust Screen Brightness and Auto-Lock Settings

Lowering screen brightness and reducing auto-lock time can save battery life. Set auto-lock to 30 seconds in Settings > Display & Brightness > Auto-Lock, and adjust brightness through the Control Center or Display settings​​.

  1. Turn Off Location Services for Unnecessary Apps

Location services can be a significant battery drain. Go to Settings > Privacy > Location Services and adjust the settings for each app, limiting access to "While Using the App" or "Never" when possible​​.

  1. Use Dark Mode and Static Wallpapers

If your iPhone has an OLED display, enabling Dark Mode can extend battery life. Additionally, using static wallpapers instead of animated ones reduces battery consumption. Turn on Dark Mode in Settings > Display & Brightness​. Go to Settings > Wallpaper and choose a static image instead of an animated one​.

  1. Manage Notifications With Scheduled Summaries

Limiting notifications can prevent your screen from waking up frequently. Go to Settings > Notifications and turn off notifications for non-essential apps. Using Focus modes can also help manage notifications and reduce battery drain. Relegating non-important notifications to a scheduled summary can reduce how often your screen lights up. Go to Settings > Notifications > Scheduled Summary and specify which apps should have their notifications included in the summary​.

  1. Turn On Airplane Mode in Low Signal Areas

When in areas with poor signal, your iPhone works harder to stay connected, draining the battery. Turning on Airplane Mode in such situations can save power until you reach an area with a better signal​.

  1. Avoid Extreme Temperatures

Extreme temperatures can degrade your battery. Keep your iPhone within the recommended temperature range of 0°C to 35°C (32°F to 95°F) to maintain battery health. Remove the case if the phone gets hot while charging.

  1. Embrace Partial Charges

Remember, frequent top-ups are your iPhone battery’s best friend! Aim to keep your phone above 20% (that yellow icon is your cue) and avoid letting it dip below 10%. This minimizes full cycles and extends your battery's lifespan.

  1. Fast Charge Wisely

While a quick power-up is tempting, fast charging generates more heat. Don't rely on it as your daily routine. Use it strategically when you're in a pinch, and let your phone cool down before subsequent charges.

  1. Turn Off Keyboard Haptic Feedback

Disabling the haptic feedback on your keyboard can save battery. You can do this by going to Settings > Sounds & Haptics > Keyboard Feedback and turning off Haptic​.

  1. Disable Automatic Mail Fetch

Fetching emails less frequently or manually can extend battery life. Go to Settings > Mail > Accounts > Fetch New Data, turn off Push, and select Manual for all accounts​​.

  1. Use Wi-Fi Whenever Possible

Using Wi-Fi consumes less power than cellular data. Connect to Wi-Fi whenever possible to save battery life​.

  1. Turn Off Raise to Wake

Disabling the Raise to Wake feature can prevent your screen from turning on unintentionally. Go to Settings > Display & Brightness and turn off Raise to Wake.

  1. Remove Cases While Charging

Removing your phone case while charging can prevent overheating, which can degrade the battery. This is especially important during wireless or fast charging sessions​.

  1. Refrain from Using Your Phone While Charging

Using your phone for graphically demanding tasks while charging can generate heat and strain the battery. Minimizing use during charging can help maintain battery health​​.

  1. Consider Powering Off At Night

While overnight charging is safe, turning your phone off completely gives the battery a much-needed rest. This can be especially beneficial if you're a light sleeper and don't need notifications right away.

  1. Upgrade Your iPhone Sustainably

Newer iPhones like the iPhone 15 or iPhone 14 generally boast more efficient batteries and processors. Upgrading to a newer model can be a long-term solution if you're a heavy user and battery life becomes a major concern.

By following these tips and dispelling the battery myths, you can enjoy your iPhone with confidence, knowing you're giving its power source the best possible care. And for even more in-depth knowledge, check out Apple's official battery health resources here.

iPhone Charging Techniques Explained

Fast Charging

Fast charging allows you to charge your iPhone significantly faster than standard charging. It uses higher wattage chargers (18W or higher) to quickly replenish the battery. To safely use fast charging:

  • Use Official or Certified Chargers: Ensure you use Apple’s official fast chargers or certified third-party chargers that meet the necessary safety standards.
  • USB-C to Lightning Cable: Use a USB-C to Lightning cable to connect your iPhone to the fast charger.
  • Monitor Temperature: Fast charging can cause your iPhone to heat up. Avoid charging in direct sunlight or hot environments to prevent overheating​.

Wireless Charging

Wireless charging offers convenience by eliminating the need for cables. Simply place your iPhone on a Qi-compatible wireless charging pad to start charging. Here are the benefits and potential drawbacks:


  • Convenience: No need to plug and unplug cables, reducing wear on the charging port.
  • Ease of Use: Ideal for quick top-ups throughout the day.


  • Heat Generation: Wireless charging can generate more heat compared to wired charging, which can impact battery health over time.
  • Slower Charging: Typically slower than fast wired charging, making it less ideal for quick full charges.

To minimize heat and maximize efficiency, use high-quality, certified wireless chargers from reputable brands when possible​.

Battery Packs and Cases

For extended usage, consider using battery packs and cases. Here are some recommendations from Reboxed’s Experts:

  • Apple Smart Battery Case: Designed specifically for iPhones, it provides extended battery life and integrates seamlessly with iOS for battery monitoring.
  • Anker PowerCore: Known for their reliability, Anker’s portable power banks offer high capacity and fast charging capabilities, ensuring your iPhone stays powered on the go.
  • Mophie Juice Pack: Another reputable brand, Mophie offers battery cases that provide extra power without compromising on protection and design.

When choosing a battery pack or case, look for features such as high capacity (measured in mAh), fast charging support, and solid safety features to prevent overcharging and overheating.

When and How to Replace Your iPhone Battery

Signs of Battery Deterioration

As your iPhone battery ages, it may exhibit several signs of deterioration. These indicators suggest it's time to consider a battery replacement:

  • Quick Draining: If your battery percentage drops significantly within a short period, it’s a clear sign of wear.
  • Unexpected Shutdowns: Your iPhone shuts down unexpectedly even when it shows a significant battery percentage remaining.
  • Slow Performance: Noticeable lag in performance due to battery health impacting processing power.
  • Overheating: The device gets unusually hot during charging or regular use.
  • Battery Health Notification: iOS might alert you that your battery’s health is significantly degraded and recommend service​​.

Battery Replacement Options

If your iPhone shows signs of battery deterioration, you have several options for battery replacement:

  • Apple Store: Visit an Apple Store or an Apple Authorized Service Provider. Apple offers battery replacement services, which can be free if your device is under warranty or AppleCare+.
  • Certified Repair Centers: Use Apple’s support website to find certified repair centers that provide genuine Apple parts and services.
  • DIY Kits: For the tech-savvy, DIY battery replacement kits are available online. Ensure you purchase from reputable sources to get high-quality components and follow detailed guides.

Reboxed - Shop refurbished phone deals with like-new batteries

At Reboxed, we ensure all our refurbished iPhones come with batteries that meet our high-quality TechCheck® standards. Each device undergoes thorough testing and battery health checks to guarantee optimal performance. If you need a battery replacement, Reboxed offers:

  • Certified Technicians & Genuine Apple Products: Our certified technicians use genuine Apple-certified batteries to replace bad batteries, ensuring every device sold functions like brand new.
  • Quality Assurance: Every refurbished iPhone is backed by a warranty that covers battery health, giving you peace of mind.

By choosing Reboxed, you not only get a reliable battery through our refurbished iPhone range but also contribute to a more sustainable environment.

We hope you can now enjoy your iPhone with confidence, knowing you're giving its power source the best possible care!

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