Marques Brownlee sparks controversy after YouTuber questions safety and long term risks of silicon carbon smartphone batteries

The tech community lit up this week after a new video from Marques Brownlee, better known as MKBHD. In the video, released on February 7, 2026, he spoke about silicon-carbon smartphone batteries and why they are still rare in major flagship phones.

His main point was simple. Even though this battery tech can hold more power than older graphite batteries, companies are holding back because of safety and long-term use concerns.That message quickly caught attention. Silicon-carbon batteries sound like the future, especially as phone battery sizes keep growing in milliampere-hours. But Brownlee’s explanation about possible swelling and wear sparked strong reactions.

Some viewers found his breakdown helpful. Others were not convinced and felt key proof was missing. Within hours, the video turned into a full-blown debate across comment sections and social media.

Marques Brownlee explains silicon-carbon battery risks as viewers question his claims

In his video titled “The Problem with These Smartphone Batteries,” Marques Brownlee said he spoke to people inside phone companies to understand why silicon-carbon batteries are not everywhere yet. He shared that the main worries are swelling and long-term durability.

He said in full quote, “There are some concerns with silicon-carbon batteries… about swelling and longevity… I went digging, and I reached out to a couple of other sources and people that I know at these companies.

”Brownlee also explained how the technology works in simple terms. During charging, silicon absorbs lithium ions and expands. He described it clearly, saying, “The silicon can expand to three times its original volume… imagine a sponge that triples in size when wet and then shrinks back down.”

Over time, that repeated movement can cause cracks and faster battery wear.The controversy grew after viewers noticed a OnePlus phone used in the video thumbnail. Some felt the brand was unfairly targeted. One user wrote, “Why the clickbait thumbnail though?! Throwing OnePlus under the bus for nothing.” Others accused him of bias, while several viewers pushed back on his claims, saying silicon-carbon batteries have already been used for years without major issues.Critics also asked for harder evidence. One comment read, “No real data, no proof just hypothetical talk.” Another said, “This tech has been in phones for two years. No reports of swelling.” Brownlee did not accuse any brand of wrongdoing, but the lack of public data left room for doubt.The discussion shows how sensitive battery safety is for users. Even trusted voices face pushback when claims feel incomplete. Whether silicon-carbon batteries become common soon or not, the debate around them is far from over.