Originally published at: iSpec the Body Electric: Exploring iPhone Battery Life Metrics - TidBITS
In a Daring Fireball link to Marques Brownlee’s review of the iPhone 18 Pro, John Gruber responded to Brownlee’s question about why Apple doesn’t publish battery life specs in mAh, saying:
In some ways this is a little silly, but the way Apple thinks about it is that they only publish specs that they think are useful for comparison. Storage is useful for comparison, so Apple dutifully publishes storage capacities. In fact that is the spec by which they price higher tiers. Battery life is useful for comparison, so Apple publishes that as a spec, based on multiple use cases. But mAh capacity of the battery, to Apple’s mind, isn’t useful for comparison.
Gruber is correct that mAh isn’t a useful spec for consumers trying to evaluate an iPhone model’s battery life. However, I have long been bothered by the video playback spec Apple has focused on since 2019, because it’s just as nonsensical as mAh. Does the fact that the iPhone 18 Pro can play video nonstop for 36 hours tell you anything useful? How would that be reflected in real-world use, since no one plays video nonstop for that long on battery? We can learn that it is better than the iPhone 17 Pro, which could only play video for 33 hours, but does that mean the iPhone 18 Pro will last 9% longer in real life? It’s a mess, and it makes Apple’s new “Typical use” metric all the more welcome.
I started wondering how Apple has changed the specs it reports for iPhone battery life over the years, and whether there was any way to visualize how battery life has improved over the iPhone’s 19-year history according to Apple’s specs. But this would involve collecting and analyzing data for 55 iPhone models—clearly, a task for an AI agent! I told Claude what I wanted, and after a bit of back-and-forth, it created several tables based on Apple’s tech spec pages and other published information—yes, I spot-checked the results. Then I had it graph that information, and the results were fascinating.
I have published the full data tables on a standalone page, and all the graphs below are on another page. The table page contains links and footnotes explaining everything, and you can hover over the data points in the graphs to see which iPhone they connect to.
Just the Specs, Ma’am
What battery life specs has Apple used over the years? In the early days, when the iPhone was used more as an actual phone, Apple emphasized traditional specs like talk time and standby time. Later, the company dropped those specs and focused on audio and video playback times; this year, Apple introduced the new “typical use” spec.
Since 2014 with the iPhone 6, Apple has published a General Battery Information page that explains how each test was performed. It’s easy to get into the weeds with the details (and Claude certainly did—down, boy!), but I wanted to focus at a higher level, with graphs showing how the measurements have changed over time. The seven specs that Apple has used over the years are:
- Talk time (2007–2018): The talk time spec measured a continuous voice call until the battery was exhausted. Early on, this spec was important because people spent a lot of time talking on the phone and could judge whether the iPhone’s talk time would meet their needs. Each network type (2G, 3G, and LTE) had radically different talk times, so Apple reported them separately. Looking at the chart, you can see that talk times didn’t improve much, apart from the big jump in 2014 with the plus-size phones and their larger batteries.
- Standby time (2007–2016): For standby time, the phone sat idle, registered on the cellular network, until it died. As with talk time, standby time made more sense in the phone-call era, because people often didn’t use their phones for much else when they weren’t talking on them. As the chart shows, standby time wasn’t particularly interesting, and it didn’t change much. I’m surprised Apple kept reporting it as long as it did.
- Internet use (2007–2018): A footnote in a page captured in a lawsuit shows that the original iPhone Internet use test used a closed network with a dedicated Web and mail server, “simulating browsing to 20 popular URLs and checking mail once an hour,” run separately over Wi-Fi and EDGE. Although this spec improved over time, it’s surprising that Apple maintained it for so long, given how radically real-world Internet usage changed over its lifespan.
- Audio playback (2007–2025): This spec relied on a playlist of 358 unique tracks played until the battery died. Intriguingly, for the Pro models from the iPhone 14 Pro through the 16 Pro Max, Apple ran the test with the Always-On display enabled but face down, warning that playback time drops when the display is visible. Why did Apple drop audio playback from the spec sheets after the release of the iPhone 16e? From a marketing perspective, it’s not a clear upward trend, and from a technical perspective, audio playback may not exercise the iPhone’s subsystems in an informative fashion at this point.
- Video playback (2007–present): Video playback is Apple’s most stable test. On the one hand, that’s odd, given that it would seem to measure an uncommon use case. On the other, video playback isolates a narrow, tightly controlled workload—decoded by a dedicated hardware block (the Media Engine), not the CPU or GPU—so the numbers stay comparable in a way radio-dependent specs never could. In addition, that graph looks great, so Apple’s marketing department undoubtedly was in favor of focusing on this spec over others. The notes describe the test playing “a repeated 2-hour 23-minute movie purchased from the iTunes Store,” stored on the phone and looped until the battery dies. Apple has never named the film, but Claude suggests that, based on the running time, release date, and later HDR release, it’s Pirates of the Caribbean: The Curse of the Black Pearl. Any Apple insiders want to confirm?
- Streamed video (2019–present): Eventually, streaming became more common than purchasing movies, so Apple added this spec with the iPhone 11, and it too shows a nice upward trend. It measures playback time for “a repeated 3-hour 1-minute movie purchased from the iTunes Store.” Claude is pretty sure that it is Avengers: Endgame, which is the right length and came out at just the right time. Any confirmation here?
- Typical use (2026–present): Finally, a sensible spec! Introduced this month with the iPhone 18 Pro, 18 Pro Max, and iPhone Duo, “typical use” is Apple’s first mixed-use rating. The notes describe a representative usage profile that “is based on the median usage values across iPhone users and reflects a combination of passive and active use of a variety of applications, including but not limited to messaging, photos, music, social media, video streaming, games, web browsing and navigation. iPhone Duo typical use based on equal usage between inner and outer displays.” It’s the only metric derived from customer behavior, and I’m glad it includes navigation, which drains battery faster than anything else. Obviously, there’s not enough data here to chart anything, but I’m curious to see if Apple improves this spec in every subsequent generation of iPhones for the foreseeable future.
Ultimately, I came away from the exercise realizing that specs like battery life, which must be determined from an extremely rigid and reproducible set of tests, will always be somewhat unsatisfying because they serve two masters: engineering and marketing.
From the engineering perspective, Apple needs to show that its hardware enhancements actually make a difference, and, more to the point, that new features don’t cause battery life to drop. Bigger, brighter screens and faster, more capable processors consume vastly more power, but battery size and efficiency also improve, and clever engineering tricks, like slowing down the screen refresh rate when it doesn’t matter, can make a big difference. As you can see in this chart, Apple has steadily increased the energy capacity of iPhones, measured in watt-hours. (The cell voltage of Apple’s batteries has crept up over time, so watt-hours doesn’t scale directly with milliamp-hours—the equation is Wh = (mAh × V) ÷ 1000.)
But marketing is just as important. iPhones are premium devices, and while they don’t necessarily have the best raw battery life (I’m sure there are Android phones out there with much larger batteries), they have to be very good and continually improve. With each successive iPhone release, Apple needs to be able to say that battery life has gotten better, preferably noticeably better. When it can’t do that, such as with last year’s iPhone Air, which had less space for a battery, reviewers and consumers alike notice and comment on it (see “Overlooked Details of the iPhone Air,” 12 September 2025).
In recent years, I think Apple has relied too heavily on the video playback specs because they are nonsensical. Yes, the numbers get better every year, and Apple executives can enthuse about how much one iPhone has improved over the previous one, but no one has any intuition for what 33 hours of video playback time means. As a result, I have high hopes for the new “typical use” spec. It may vary from your actual use, but it feels real in a way that the other specs never have.