What iPhone Has the Best Battery Life?

Considering the frequency with which people use their phones, it’s understandable that you’d want to ensure you’re getting your money’s worth with your iPhone. While some consider camera features or storage space top priorities, what’s the point of having both if your battery dies too quickly? 

Discover which model is best for battery life and how you can extend the battery life of your current device without limiting your experience.

Latest iPhones Ranked by Battery Life

So, which device comes out on top based on battery life alone? 

iPhone 18 Series and iPhone Duo

Apple's newest iPhones just landed as of September 2026, and they've already reset the bar. The iPhone 18 Pro Max is rated for up to 45 hours of video playback, six hours more than last year's iPhone 17 Pro Max, with up to 30 hours of real-world use per charge.

The iPhone 18 Pro isn't far off either, at up to 36 hours of video playback, which is about the same as last year's Pro Max. Only the Pro and Pro Max are out right now, since the standard iPhone 18 isn't dropping until spring 2027.

The iPhone Duo was also announced alongside the 18 series. It’s Apple's first foldable, launching October 23. It runs on two batteries and gets up to 44 hours of video playback on its outer display or 31 hours unfolded, but since it's such a different kind of device, we're leaving it out of the ranking below.

iPhone 17 Series

The iPhone 17 series showed up in September 2025 with four models: iPhone 17, iPhone 17 Pro, iPhone 17 Pro Max, and the super-thin iPhone 17 Air. Before the 18 series took over, the Pro Max was the battery life champ at up to 39 hours of video playback.

The standard iPhone 17 got a nice bump too, up to 30 hours of video playback, a full 8 hours more than the iPhone 16. The Air trades some battery for its slim build, landing at up to 27 hours.

iPhone 16 Series

It may come as no surprise that with 57% of US adults addicted to their phones, the demand for increased battery life for extra usage is rising. With technological developments, the iPhone 16 was, at the time of its release, among the best on battery life.

The 16 series boasts the bigger batteries at 4,685 mAh for the Pro Max and 4,674 mAh for the iPhone 16 Plus. Bigger batteries don’t always mean a longer life. While the iPhone 16 Pro Max leads the 16 series for a battery life of approximately 11 hours, the 15 Pro Max beats the 16 Plus by nearly an hour. 

However, the iPhone 16 series beats all the other models on battery life overall. 

iPhone 15 Series 

While several devices beat the iPhone 15 from the 14 series, it’s crucial to note that the 15 Pro Max and the iPhone 15 Plus rank high overall, with the former beating the latter. While the 14 model is tough competition for the 15 series, the latter remains higher overall than the previous series. 

However, it’s worth remembering that the iPhone 15 Pro Max overcomes the battery life of some in the 16 series, so you don’t always need to pay more for the latest model for better battery life. 

iPhone 14 Series 

The iPhone 14 series has some real disparity in battery sizes, with the 14 model measuring 3,279mAh while the 14 Pro Max 4,323mAh. With this in mind, it’s no surprise that the iPhone 14 Pro Max has about three more hours of video playback than its older counterpart. 

That being said, the 14 series does measure well overall, as the 14 Pro Max is among the top for battery life, and the iPhone 13 series (aside from the iPhone 13 Pro Max, which falls short of the younger models). 

iPhone 13 Series 

While the 13 series doesn’t match up to that of the iPhone 14, 15, or 16 series, it’s worth bearing in mind that most of the models’ battery sizes are considerably smaller (excluding the Pro Max with its battery at 4,352mAh). While the battery life is generally lower, the iPhone 13 can still offer up to 20 hours of video playback, which is no small feat and should satisfy anyone using their phone for long durations. 

Again, the Pro Max versions in each series seem to beat most other models in the younger series, as the iPhone 13 Pro Max has better video playback than all other models in the 14, 15, and 16 series aside from the Pro Max designs of those younger series.  

iPhone 12 Series 

If you have an iPhone 12 series device, is it worth it? Or should you upgrade to a newer model? Remember that any time you upgrade, you consider the damaging environmental impact of discarding your old phone. The devices in the 12 series are not as good for battery life as those in the younger generations. 

However, the 12 model offers a similar charge to the iPhone 13, so that comparative battery life isn’t perhaps enough reason to throw away your current device.

iPhone 11 Series 

The iPhone 11 series was released in 2019. Unsurprisingly, the 11 series doesn’t surpass those of the younger generations. With a battery size of 3,110mAh, the iPhone 11 does have a bigger capacity than some of the younger generation models. However, this cannot even raise the 11 series through the ranks.

iPhone Battery Sizes

Some of these vary slightly by SIM tray vs. eSIM-only model, so treat them as close estimates rather than exact figures:

1. 18 Pro Max (SIM tray) - 5,391 mAh
2. 17 Pro Max (eSIM) - 5,088 mAh
3. 16 Pro Max - 4,685 mAh
4. 16 Plus - 4,674 mAh
5. 15 Pro Max - 4,422mAh
6. 15 Plus - 4,383mAh
7. 13 Pro Max - 4,352mAh
8. 14 Pro Max - 4,323mAh
9. 17 Pro (eSIM) - 4,252 mAh
10. 18 Pro (SIM tray) - 4,056 mAh
11. 17 - 3,692 mAh
    
12. 16 Pro - 3,582 mAh
13. 16 - 3,561 mAh
14. 15 - 3,349 mAh
15. 14 - 3,279mAh
16. 15 Pro - 3,274mAh
17. 17 Air (eSIM) - 3,149 mAh
    

Which iPhone Has the Longest Battery Life?

While many factors will affect battery life, and different bodies will use differing methods to understand which comes out on top, the iPhone 18 Pro Max is now the model to beat. While this might be unsurprising to some due to its size, its video playback is approximately 45 hours, and Apple rates it for up to 30 hours of everyday mixed use on a single charge.

The only iPhone that comes close is the Duo, which hits 44 hours on its outer display, but that's a different kind of device altogether.

What Can I Do To Prolong My iPhone's Battery Life?

1. Ensure you have the latest software 

Ensure that you have the latest software on your device to optimise battery life. 

2. Use Battery Saving Settings 

When using battery-saving settings, such as auto-brightness, you’ll ensure you aren’t using more battery-draining settings. If you’re concerned about how to prolong your phone's life, it is best to check its health.

3. Use Low Power Mode 

Keeping your device in lower power mode (introduced with iOS 9) ensures you can still use critical essential functions, such as making and receiving calls and messages, accessing the internet, and receiving emails. Still, it also considerably saves your battery life. 

4. Don’t Over or Under Charge

Preserving your battery’s health is paramount when giving your phone the best chance of survival. Leaving your phone to charge overnight isn't always the best idea. It's generally recommended not to keep your phone plugged into charge once fully charged, as this can damage your battery's lifespan.

Final Thoughts

Battery life may not be the most crucial factor when choosing a phone. However, long or short battery life won’t protect your phone from damage, and what’s the point of having a good battery life if your phone ultimately breaks because you don’t have a case? 

Don’t hesitate to protect your device so it lives a long life with Casely’s range of iPhone cases today!