Silicon-carbon batteries have changed the game — Apple and Samsung need to catch up

Smartphone battery capacity is undergoing a revolution at the moment, thanks to increasingly mainstream silicon-carbon battery technology found in high-end handsets. Even the notoriously slow Samsung has adopted it in its latest Galaxy Z Fold 8 series. What started out as a reasonably modest boost to 6,000 mAh capacities has quickly reached 8,000 mAh and even 10,000 mAh models, almost doubling battery capacity potential in just a few short years.

I’ve had the new OPPO Find X10 Pro Max in my pocket for the past few weeks, itself sporting an 8,000mAh Si-C cell. Though I should note that global models ship with a slightly reduced 7,150mAh split-cell design. OPPO claims that both models are sufficient for two days of typical use, and I’ve put my handset through our testing wringer to find out just how much longer it can endure compared to rival flagships.

For today’s comparison, I grabbed our reigning battery champion — the OnePlus 15 — sporting an already massive 7,300 mAh cell. I also picked up my Samsung Galaxy S26 Ultra (5,000 mAh) and Google Pixel 11 Pro XL (5,100 mAh)to see how these next-gen batteries compare to more traditional cells found in popular flagship phones. Let’s jump into the endurance results.

How long does an 8,000mAh battery last?

The results are pretty conclusive, then. The OPPO Find X10 Pro Max’s 8,000mAh battery clearly helps against the already mighty impressive OnePlus 15. Among these phones, OPPO’s latest flagship sits comfortably at the top table across all five of our test scenarios — 4K video playback, 4K video capture, photo capture, web browsing, and Zoom video calls. It’s worth considering that the chip has a newer 2nm MediaTek Dimensity 9600 onboard, which could help the phone sip battery life compared to last-gen handsets. OPPO is also typically rather aggressive at prioritizing efficiency over raw performance, which also leans in the phone’s favor in these battery tests. Battery life isn’t just about the size of the cell but also about how much power the system draws.

Nevertheless, an 8,000 mAh battery is clearly a boon for use cases where hardware is the major power draw. The OPPO Find X10 Pro Max offers impressive photo and 4K video capture, enabling over eight hours of continuous shooting. That is more than twice what the Samsung Galaxy S26 Ultra can do and almost three hours of additional filming time than the Google Pixel 11 Pro XL, translating into a very different experience for shutterbugs.

Having used the phone extensively for the past three weeks, I can definitely say that these results play out in everyday use as well. The OPPO Find X10 Pro Max lasts me through two days of typical use — scrolling the web, sending messages, and snapping the odd picture — with juice to spare. I can even push into a third day of lighter use, but in that case, I usually end up charging before lunch. In both cases, it feels incredibly difficult to drain such huge batteries just by browsing the web and sending messages.

If there’s a drawback to these large batteries, it’s that they can take much longer to charge them back up. OPPO, in particular, seems rather conservative with charging power this generation, barely touching its peak 64W level before spending much of the charging cycle at closer to 30W. This leaves the phone taking a rather agonizing 80 minutes to fill up, which is even slower than the Pixel 11 Pro XL, though obviously it’s topping up a much bigger battery. You can flick on OPPO’s Smart Charging feature, but even this shaves off barely a few minutes from the charge time and doesn’t seem to make any meaningful difference to power or temperatures. Si-C charging doesn’t have to be slow, however. The OnePlus 15 managed to top up its huge battery in the same time it takes Samsung to fill the smaller S26 Ultra’s cell.

Rival brands need to catch up

Of course, it’s obvious that bigger batteries help provide longer screen-on time, but just how much of a difference modern phones make is still quite surprising. Double the content capture time and over 14 hours of web or video call time are game-changers compared to popular flagships that still charge similar prices. The difference between making it partway through the second day and all the way through is significant, especially for commuters and frequent travelers.

Of course, Ultra and Pro Max smartphones aren’t exactly cheap, often costing closer to $1,500. But you don’t have to buy the most expensive phones on the market to benefit from huge battery capacities. The REDMI Note 17 Pro Max is a mid-range phone with a huge 10,000mAh battery and a very modest £499 price tag. The OnePlus 15 used for this test has a mainstream flagship price tag of $900, and the more affordable OnePlus 15R costs a reasonable $699.

Silicon-carbon-equipped smartphones are a game-changer for multi-day battery life, but it’s a real shame that they haven’t made their way into other brands’ phones yet, even though it’s been three years since the first such phone hit global markets.  Outside of its latest booklet foldables, Samsung has yet to embrace the technology for its mainstream S-series flagships. Rumors suggest bigger capacities might be coming to the Galaxy S27 series, but nothing approaching the mammoth batteries we’ve tested today. Likewise, Apple and Google could finally dispel reputations for dubious battery life by brute force if they jumped on the Si-C bandwagon.

Maybe next year? Until then, I’ll find it very hard to switch back.