Finally! Samsung officially joins bigger battery race with new Galaxy flagship

Samsung Galaxy Z Fold 7 — (Image credit: Basil Kronfi)

Quick Summary

Following "years of work", Samsung has finally presented its first phones to feature a silicon-carbon (Si-C) battery type.

The Galaxy Z Fold 8 Ultra folding phone features a 5,000mAh Si-C cell, an upgrade over the lithium-polymer (Li-Po) type of its predecessor. The all-new Z Fold 8 and Z Flip 8 also feature different capacity Si-C batteries.

This could be a major sign for the brand's future path, with the Galaxy S27 Ultra potentially in line for the upgrade.

During the Samsung Galaxy Z Fold 7 launch last summer, I queried Samsung's Minseok Kang, Head of Smartphone Product Planning, about when we might see the company release a phone with new battery technology.

He confirmed that "years of work" had already gone into testing at that stage. But now the wait is finally over – as the all-new Samsung Galaxy Z Fold 8 and 8 Ultra each feature a silicon-carbon (Si-C) battery type. That's a first for the Korean giant.

But it's far from a first for the industry, which is why so many have been querying when the mobile-maker would invest in the higher-density battery technology. After all, a key function of Si-C is greater longevity as a result, or the option of utilising less space in a design without compromising.

History lesson

I'm not surprised there's been an extended wait, though. It was almost a decade ago when the launch of the Galaxy Note 7 prompted a recall after risk of fire was identified. Ever since then Samsung has been cautious in pushing ultra-capacity batteries or the fastest-charging technologies.

“When Samsung apply or implements the battery, we consider three key points: one is the size; second is the charging speed; and the third one is safety – the reliability of that battery. We think a little more priority on the reliability is best practice," Kang said to me 12 months ago.

Clearly there's been ample testing time for Samsung's testing processes to be passed for these product lines. While it was initially thought that only the Ultra would feature such a battery, Samsung has confirmed it's that device, plus the all-new Z Fold 8 – which some have dubbed the 'Wide', given its less tall and wider ratio – and Z Flip 8 products.

A glimpse of the future

For future Samsung products I think this marks big potential to see further leaps forward. The Galaxy S27 Ultra is prime for a key update or two come next year – with battery being an area where it's stagnated. Sure, its 5,000mAh cell is perfectly capable, but when Oppo is delivering a 7,500mAh in its Find X9 Pro flagship, it's clear where the market is going.

Samsung can no longer afford to sit behind the pack, depending on its loyal customer base. But the Galaxy Z Fold 8 series is proof that it's put the work in to keep up with the times – and on its own terms. And a safety first approach is no bad thing, even if a bit of patience has been required.

There's a whole lot going on around Samsung's second Galaxy Unpacked event of 2026, with the Z Fold 8, Z Fold 8 Ultra, Z Flip 8 and Watch Ultra 2 launches the major headlines. Keep your eyes on T3 for more, as we'll be reporting live and direct.

Mike is T3's Tech Editor. He's been writing about consumer technology for 15 years and his beat covers phones – of which he's seen hundreds of handsets over the years – laptops, gaming, TV & audio, and more. There's little consumer tech he's not had a hand at trying, and with extensive commissioning and editing experience, he knows the industry inside out. As the former Reviews Editor at Pocket-lint for 10 years where he furthered his knowledge and expertise, whilst writing about literally thousands of products, he's also provided work for publications such as Wired, The Guardian, Metro, and more.