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iPhone 12 battery life results: All four models compared

iPhone 12 battery life
(Image credit: Future)

We've now run all of the new iPhone 12 models through our battery test, and the results are mixed. The iPhone 12 mini is the smallest of the bunch and has a small battery to match, turning in the shortest runtime over 5G. The iPhone 12 and iPhone 12 Pro lasted longer but are a step behind competing Android phones.

Based on our tests the iPhone 12 Pro Max is the one to get if you want the longest endurance and fares well against Android phones. It doesn't quite break the 11-hour mark to land on our best phone battery life list, but it's close. 

Here's how the Tom's Guide battery test works. It surfs the web continuously at 150 nits of screen brightness, launching a new site every 30 seconds until the battery drains. For the iPhone 12 and iPhone 12 Pro, we ran this test over 5G and 4G, and the difference was pretty dramatic.

While it's not the only factor, we've included the size of the battery for each phone listed below. The iPhone 12 and iPhone 12 Pro battery sizes are based on certifications and teardowns, as Apple does not list battery capacity as part of its specs.

iPhone 12 and iPhone 12 Pro battery test results

Battery life (hrs:mins)Battery size (mAh)
iPhone 12 mini (5G)7:282,227 mAh
iPhone 12 (5G)8:252,815 mAh
iPhone 12 Pro (5G/)9:062,815 mAh
iPhone 12 Pro Max (5G/)10:533,687 mAh
iPhone 11 (4G)11:163,110 mAh
iPhone 11 Pro (4G)10:243,046 mAh
Galaxy S20 5G (60Hz/120Hz)9:31/8:044,000 mAh
Galaxy S20 Plus 5G (60Hz/120Hz)10:31/8:554,500 mAh
Galaxy S20 Plus Ultra 5G (60Hz/120Hz)12:03/9:135,000 mAh
OnePlus 8T 5G (60/Hz/120Hz)10:49/9:584,500 mAh
Google Pixel 5 (60Hz/90Hz)9:56/9:294,080 mAh

iPhone 12 mini battery life

The iPhone 12 mini has a small 2,227 mAh battery, so it's not a big surprise that this phone lasted only 7 hours and 28 minutes on our web surfing battery over 5G. The iPhone SE 2020 lasted a considerably longer 9:18 with an even smaller 1,821 mAh battery. However, we conducted that test over 4G, which uses less power. 

iPhone 12 battery life

The regular iPhone 12 lasted just 8 hours and 25 minutes over AT&T's 5G network. Last year's iPhone 11 lasted a whopping 11 hours and 16 minutes over 4G. To compare, we switched the iPhone 12 to 4G-only, and it endured for 10 hours and 23 minutes. 

Samsung's Galaxy phones generally last longer on a charge over 5G, though they lose a lot of juice when their screens are set to the faster 120Hz refresh rate. For example, the Samsung Galaxy S20 lasted 9:31 on 5G but that dipped down to 8:04 at 120Hz.

Google's Pixel 5 was nearly an hour better than the iPhone 12 at 9:56; it dropped to 9:29 with the screen set to a faster 90Hz refresh rate. Both of those times are well ahead of the iPhone 12's 8:25 result over 5G. 

iPhone 12 Pro battery life

The iPhone 12 Pro fared a bit better, lasting 9 hours and 6 minutes minutes over T-Mobile's 5G network. That runtime jumped to 11:24 over 4G. The iPhone 11 Pro lasted 10:24 over 4G.

The similarly priced Samsung Galaxy S20 Plus lasted 10:31 over 5G, which is nearly 1.5 hours longer than the iPhone 12 Pro. The runtime of Samsung's phone dropped to 8:55 at 120Hz, which is slightly worse than the iPhone 12 Pro over 5G. 

To be fair, the Galaxy S20 Plus has a larger 4,500 mAh battery, while the iPhone 12 Pro is rated for 2,815 mAh.

iPhone 12 Pro Max battery life

Now we're talking. The iPhone 12 Pro Max's 3,687 mAh battery lasted a very impressive 10 hours and 53 minutes over 5G. That beats the iPhone 12 Pro by nearly two hours. The Galaxy S20 Ultra with its much bigger 5,000 mAh battery endured for 12 hours and 3 minutes, which fell to 9:13 in 120Hz display mode.

iPhone 12 battery life: Bottom line

Of course, our web surfing test is just one way to measure battery life. And we know that no one is going to surf the web for 10 or 11 hours straight. But this test does give us a way to compare endurance across multiple phones, even if it is a taxing test.

When you're not surfing the web, the iPhone 12's Smart Data mode can automatically switch to 4G to help save battery life. But this only kicks in during certain scenarios, such as when you're streaming music with the screen turned off.

Overall, the iPhone 12 and iPhone 12 Pro battery life is a bummer over 5G, at least when surfing the web. So you may want to manually switch to 4G in some cases to save extra juice. 

  • moibensa
    By 5g do you mean iPhone was set to 5G only or with Smart Data?
    Also, it’s important to take into account the battery sizes. The iPhones have much lower battery maH but perform far better due to advanced chipsets and hardware+software collaboration
    Reply
  • djonbellis
    moibensa said:
    By 5g do you mean iPhone was set to 5G only or with Smart Data?
    Also, it’s important to take into account the battery sizes. The iPhones have much lower battery maH but perform far better due to advanced chipsets and hardware+software collaboration

    Battery size indeed needs to be taken into consideration here. When it is, iPhones actually look a lot better than the rest. 2,775mAh in iPhones vs. 4,000-4,500mAh on the others. See Below:

    Seconds of surfing per mAh of battery drain:
    iPhone 12- 10.92 sec
    iPhone 12 Pro- 11.81 sec
    Galaxy S20- 8.57 sec
    Galaxy S20 Plus- 8.41sec
    OnePlus 8T- 8.65 sec
    Pixel 5- 8.76 sec
    Reply
  • JustAnotherNobody
    I'm sure when your iPhone battery runs out at 3:30pm, you'll be happy knowing that it performs better per mAh than other phones.

    You'll just be wishing you had more of those mAh...
    Reply
  • moibensa
    JustAnotherNobody said:
    I'm sure when your iPhone battery runs out at 3:30pm, you'll be happy knowing that it performs better per mAh than other phones.

    You'll just be wishing you had more of those mAh...

    Fair point but less mAh is what allows the phone to be thinner and lighter. That’s what Apple goes for—not saying it’s what is most important for me. As far as charge, they were able to add 5G reduce the battery size and keep battery performance (according to them) just like the previous gen iPhone 11 Pro, and that in it if itself is an accomplishment. I’d be more interested to see this report with Smart Data vs 5G only
    Reply
  • ikjadoon
    5G battery life reductions were quite predictable. But, what actual settings did you use? There are six total options available for 5G vs 4G. You have no methodology in this article nor the iPhone 12 / 12 Pro reviews.

    Question 1: Are your "5G" results with 5G On or 5G Auto?


    Question 2: What data mode was used? Allow More Data on 5G, Standard, or Low Data Mode?


    Question 3: Why on Earth were some iPhones on T-Mobile's 5G and others on AT&T's 5G?

    The regular iPhone 12 lasted just 8 hours and 25 minutes over AT&T's 5G network.

    The iPhone 12 Pro fared a bit better, lasting 9 hours and 6 minutes minutes over T-Mobile's 5G network.

    This article is genuinely incomplete. You need a rigorous testing environment (and reviewer) to publish accurate battery life results. Hope to see these corrected in this article or in a follow-up.
    Reply
  • Mark Spoonauer
    moibensa said:
    By 5g do you mean iPhone was set to 5G only or with Smart Data?
    Also, it’s important to take into account the battery sizes. The iPhones have much lower battery maH but perform far better due to advanced chipsets and hardware+software collaboration
    We used default settings with Smart Data on. Smart Data doesn't help with web surfing though. We have a separate story on performance and yes it's not close with Android.
    Reply
  • Mark Spoonauer
    moibensa said:
    By 5g do you mean iPhone was set to 5G only or with Smart Data?
    Also, it’s important to take into account the battery sizes. The iPhones have much lower battery maH but perform far better due to advanced chipsets and hardware+software collaboration
    Battery size is of course a factor, but Apple doesn't publish battery sizes because it does not believe that it is an important spec. We simply wanted to show how the iPhone 12 and iPhone 12 Pro stacked up to similarly priced smartphones. Once the battery sizes become official, we will add them.
    Reply
  • Sh4veD4ve
    Was this mm-wave 5G (VZ, ATT) or sub-6 (T-Mo)?

    If it's mm-wave, yes, it's powering a whole 2nd radio (well the RF portion anyway), so of course battery life will be worse.
    If it's sub-6 like T-Mo, this is significant, because it's 1 radio, and it would be much less efficient.
    Reply
  • icancto
    how come iPhone 12 Pro lasted for about an hour longer than the regular iPhone 12?
    Reply
  • 2muaddib
    icancto said:
    how come iPhone 12 Pro lasted for about an hour longer than the regular iPhone 12?

    I think it’s the testing methodology: probably reviewer was launching similar sites in circle, so some pages remained cached in memory (6gb in Pro’s), hence less CPU and radio usage -> less power drained.
    Reply