Why some iPhones drain battery faster than others

Feels like your iPhone battery drains faster than others?

Ever noticed how your iPhone seems to run out of juice quicker than your friend’s, even if you’re both using the same model? Or maybe your new iPhone doesn’t last quite as long as expected? You’re not imagining it—some iPhones do drain battery faster than others, and several key factors contribute to that difference.

We asked Allar Satsi, Swappie’s in-house Repair Lead about the real reasons behind battery drain and what you can do to keep your iPhone powered for longer.

1. How you use your iPhone matters

Allar highlights that people vary on their iPhone usage. “Yes, I often notice that my phone holds a charge longer than my friend’s or relative’s devices. However, this is usually due to user habits rather than the phone itself. It’s worth mentioning that one of the major advantages of Apple devices is their batteries. If we’re comparing similar-sized models, and not comparing a Pro Max to a Mini or a Plus, then battery life often differs from person to person because the phone is used differently.”

“On workdays, my screen time is often just around 1–2 hours per day, while it could be that my friend’s usage can be as high as 12 hours, since he spends most of his time browsing the internet.”

2. Battery health and age make a big difference

Your iPhone’s battery is designed to retain up to 80% of its original capacity at 500 full charge cycles under normal use. As your battery ages, its ability to hold a charge decreases—so even if you’re not using your phone more than usual, it might be running out of power quicker.

You can check your battery’s current condition under Settings > Battery > Battery Health & Charging. A lower “Maximum Capacity” percentage indicates that your battery isn’t performing like it used to.

3. Some iPhones have smaller batteries

Not all iPhones are created equal when it comes to battery size. For example:

• The iPhone 13 Pro Max has a 4,352 mAh battery
• The iPhone SE (2nd gen) has a much smaller 1,821 mAh battery

Naturally, larger batteries last longer—especially when paired with power-efficient chips. Apple doesn’t officially list battery capacities on its site, but these figures have been confirmed by reliable teardown sources like iFixit.

So, if your iPhone has a smaller battery, it may drain faster even if you’re using it the same way as someone with a larger model.

4. Background activity and app usage matters

Apps running in the background, especially location-based or social media apps, can be major battery hogs. According to Apple, features like Background App Refresh, Location Services, and even push notifications can cause noticeable battery drain.

To see which apps are using the most power, go to Settings > Battery, and scroll down to view usage stats by app. Disabling unnecessary background features can make a big difference.

Allar points out, “On the other hand, if we take equal screen time, then what really matters is how the phone’s features are used. For example, I always have location services, Wi-Fi, Bluetooth, mobile data, and sound at maximum volume turned on. My smartphone is often connected to several devices at once, like headphones or a smartwatch, and all of that affects battery life. It’s also worth noting that Pro models now have higher screen refresh rates, which also require more power.”

5. Display settings can impact battery life

Higher screen brightness, longer auto-lock settings, and ProMotion displays (with adaptive refresh rates up to 120Hz on newer Pro models) can all influence battery consumption.

For example, the iPhone 14 Pro uses a dynamic refresh rate to save battery—but if the screen is left on constantly or brightness is maxed out, it still drains faster.

6. iOS version and settings play a role

The iOS version your iPhone is running can affect performance and battery life. Some updates introduce features that use more power, while others include optimizations to reduce drain. Right after an update, your iPhone may temporarily use more battery as it reindexes files and completes background tasks.

If you’re noticing increased drain after updating, give your phone a few days to settle. You can also reset settings or enable Low Power Mode to conserve energy in the meantime.

6. Network and environmental conditions

Poor signal strength forces your iPhone to work harder to maintain a connection, especially if you’re on 5G or switching between Wi-Fi and cellular data frequently. According to Apple, extreme temperatures—especially heat—can also degrade battery performance over time.

Want better battery performance? Consider a Swappie-certified iPhone

If your current iPhone is draining too fast and the battery health is dropping, it might be time to upgrade—but that doesn’t mean buying new. At Swappie, all refurbished iPhones come with:

• A battery health of at least 86%
• An option to upgrade to 100% battery health for an additional cost
• A warranty and 14-day free return policy
• Full testing through a 52-step process by in-house technicians

You get the performance of a new iPhone without the new-phone price—or the environmental impact of buying brand-new tech.