For years, phone battery life barely improved. Screens got brighter and processors faster, but most phones still needed charging every night. That’s finally changing, thanks to a new battery material: silicon-carbon.
What is a silicon-carbon battery?
A lithium-ion battery has two sides, and one of them, the anode, has traditionally been made of graphite. Silicon can store far more lithium than graphite, which means more energy in the same space. The problem is that pure silicon swells and cracks as it charges.
Silicon-carbon batteries solve this by blending silicon into a carbon structure that holds it together. The result is a battery that stores noticeably more energy in the same space.
What difference does it make?
- Much bigger capacities. Recent phones from OnePlus, Honor, Xiaomi and others now have batteries of 7,000 mAh or more, where 5,000 mAh was the norm.
- No extra thickness. The phones aren’t any chunkier.
- Two-day battery life is realistic for many people.
- Thinner phones and foldables. Makers can also use the technology to keep battery life the same in a slimmer body.
- Fast charging. Many of these phones charge fully in well under an hour.
What about Apple and Samsung?
The biggest brands have been more cautious. Battery safety is critical, shipping rules for large batteries are strict, and both companies sell in huge volumes worldwide. They’re widely expected to adopt silicon-carbon in the next couple of years, but neither has moved as quickly as the Chinese brands.
Are there downsides?
- Long-term ageing. Silicon-carbon batteries are newer, so there’s less real-world data on how they hold up after several years. Early signs are good.
- Availability. Many of the biggest-battery phones aren’t sold through UK networks, though brands like OnePlus and Honor are available here.
How to look after any phone battery
Whatever’s inside your phone, the same habits keep it healthy:
- Avoid extremes. Batteries last longest when kept roughly between 20% and 80%.
- Turn on optimised charging. iPhones and most Android phones can limit charging to 80%, or learn your routine and finish charging just before you wake.
- Keep it cool. Heat is a battery’s worst enemy. Don’t leave your phone on a sunny dashboard or under a pillow while charging.
- Use a decent charger and cable.
- Don’t worry about overnight charging if optimised charging is on.
Is your battery worn out?
Check its health:
- iPhone: Settings → Battery → Battery Health
- Samsung: Settings → Battery → Battery information (or the Samsung Members app)
- Other Android: Settings → Battery
If it’s below about 80%, or your phone dies well before the end of the day, a battery replacement will make it feel new again, at a fraction of the cost of a new phone.
💡 Tip: before you upgrade a phone because “the battery’s rubbish”, get a quote for a new battery. It’s often all the phone needs.
Wrapping up
Silicon-carbon is the biggest leap in phone batteries for a decade, and it should reach most phones over the next few years. Until then, look after the battery you’ve got, and replace it before you replace the phone.
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Sources: Tom’s Guide: Silicon-carbon batteries are the next big thing in phones · PhoneArena: Will Samsung adopt silicon-carbon batteries? · MakeUseOf: I used a phone with a silicon-carbon battery
