In my last review of the OnePlus 15R, I claimed that it had the best battery life I’ve ever experienced in a smartphone. After a month of use it seemed to be the case – now I have the numbers to prove it.
The OnePlus 15R’s 7,400mAh battery is larger than most of the best Android phones, and as I tested it day after day, I was continually impressed by how much charge was left in the tank when I went to bed. I’ve fallen out of the habit of charging my phone regularly – who knows how I’ll cope when I go back to my regular phone.
However, it’s one thing to say that the 15R has the “best battery life I’ve ever experienced” and another to prove it. So I put the handset through some tough comparisons to see how it compares to some other phones. In contrast, I had two phones on hand: the Poco X7 and the Realme 15 Pro (well, a Game of Thrones-themed special edition).
Meet your participants
In part, these phones were chosen because they were both used about as much as the OnePlus 15R; Since my normal phone is used much more often, the battery condition is not optimal.
The cell phones also cover a spectrum in terms of price; none of them are the iPhone 17 Pro Max and the Galaxy S25 Ultra, and all were released in 2025. Let’s take a quick look at some key specifications:
| OnePlus 15R | Realme 15 Pro | Small X7 | |
| battery | 7,400mAh | 7,000mAh | 5,110mAh |
| Screen size | 6.83 inches, 1272×2800 | 6.8 inches, 1280×2800 | 6.67 inches, 1220×2712 |
| Screen specifications | 1,800 nits, 165 Hz | 1,800 nits, 144 Hz | 1,200 nits, 120 Hz |
| Screen technology | AMOLED | OLED | AMOLED |
| processor | Qualcomm Snapdragon 8 Gen 5 | Qualcomm Snapdragon 7 Gen 4 | MediaTek Dimensity 7300 Ultra |
| R.A.M. | 12GB | 12GB | 12GB |
The spec list reveals other variables that can affect battery life: the screen size, maximum brightness and refresh rate, as well as processor and connectivity. Some specs I couldn’t change and are natural differences beyond the phone. For this reason, I ran a series of tests to ensure I was getting a complete picture and reflecting the overall user experience.
However, to ensure that the tests are reasonably scientific, I have kept the factors under control where possible. I relied on automated screen specifications and disabled all connectivity unless necessary. I didn’t want incessant WhatsApp notifications to eat into a phone’s power consumption if I somehow became incredibly popular.
I also turned each phone fully on before starting each test and ran them simultaneously in the same environment (except for the gaming test, as I couldn’t play on all three at the same time, but in that case I ran them back to back).
The tests
I ran five tests to try out different use cases of the three phones.
First up was the camera video recording test. I set all three phones to record in 4K at 30 frames per second (the maximum frame rate the Poco could achieve), disabled all additional recording features, turned them face down, and pressed record.
I ran two video playback tests – no, not the boring 4K tabletop footage I had just captured. In one, I played a 90-minute homemade sizzle video of my own projects that I saved internally on the phone. In the other, I played 120 minutes of a 6-hour nature video loop that I found on YouTube. I made sure there were no ads so all three phones played at the same time. Originally it was supposed to be a shorter test, but I forgot it was running.
Test three was for gaming: I launched Call of Duty: Mobile, made sure the graphics options were consistent, and played games. I made sure the experiences were consistent, jumping back into games as soon as I finished a previous one, and recording battery life at 30, 45, and 60 minutes.
The other test I did was designed to replicate simpler uses, namely staring at the screen: I pulled up the Google app (which, since Wi-Fi was off, just showed a “No connection” message) and left it for 90 minutes to see how much water was used. As you can see from the results, there wasn’t much drain, but I left the results anyway.
The results
Battery consumption per task
| Task | OnePlus 15R | Realme 15 Pro | Small X7 |
| 4K video recording (60 minutes) | 14% | 11% | 11% |
| Internal video playback (90 minutes) | 2% | 3% | 4% |
| YouTube streaming (120 minutes) | 4% | 7% | 8% |
| White screen (90 minutes) | 1% | 3% | 1% |
| Play (30 minutes) | 2% | 6% | 5% |
| Gaming (45 minutes) | 4% | 9% | 9% |
| Gaming (60 minutes) | 6% | 13% | 12% |
I would like to add a few observations: the automatic brightness adjustment made the Poco’s display This could explain some of its high scores. The Realme also had the opposite problem in the YouTube playback test – it was significantly brighter. I manually reduced the brightness until it could keep up with the other phones, which again factors into the results.
As you can see from the results, the OnePlus 15R beat or matched the other phones in almost every single test. When I was playing it wasn’t even close. Longer mobile gaming sessions would make it clear that the OnePlus’ huge powerhouse means it’s built to last, and that headroom would only increase over a longer period of time.
The result also applies to other tasks, although the margins are smaller for less intensive tasks. What’s excellent is that the OnePlus 15R only lost a single percentage of performance over 90 minutes of continuous screen-on time. What’s also fantastic is that it only lost 1% more when spending the equivalent amount of time streaming a movie-length video.
Now for the only exception: video recording. As you can see in the results, the OnePlus lost more power than its two competitors, which surprised me a little. If I had to guess, I would point out that the internal processing is better optimized on the Poco and Realme phones. I would have liked to increase the specs to see how damaging higher refresh rates are, but then the Poco wouldn’t be able to keep up.
All of these phones also have pretty good battery life; The fact that they could all stream a two-hour video without losing 10% charge would have been unthinkable a few years ago. If I had compared the OnePlus 15R to its big-name contemporaries like the Samsung Galaxy S25, the iPhone 17 or the Google Pixel 10, I think it would look even better.
Despite the battery performance, I took a lusty side-eye at the Realme 15 Pro in some tests – it performed admirably in gaming, offered more vibrant colors in the video tests and, most importantly to me, charged beautifully and quickly (like the 15R, it has an 80W output compared to the X7’s 45W).
Battery life isn’t the most important spec for everyone; Some people are never far enough from a charger to cause concern. But there are plenty of other people like me who like a good power adapter, whether because you don’t like being tied to regular charging schedules or because you often travel or vacation where charging is unlikely. So it’s great that phone manufacturers are recognizing this need and offering handsets like the OnePlus 15R.
Interested in the OnePlus 15R? It can be pre-ordered now.
