Technologies

Phone Plugged in 24/7? Experts Reveal the Science Behind Battery Damage

Phone batteries degrade over time, but heat and use habits are a larger danger than keeping your phone plugged in.

There was a time when smartphone users were warned not to leave their phones plugged in for too long, or it could do damage to the battery. While modern smartphones now have overcharge protection that keeps them safe, many people still have questions about whether keeping their phone perpetually plugged in will damage the battery.

The short answer is no. Keeping your phone plugged in all the time won’t ruin your battery. Modern smartphones are built with smart charging systems that cut off or taper power once they’re full, preventing the kind of «overcharging damage» that was common in older devices. So if you’re leaving your iPhone or Android on the charger overnight, you can relax.

That said, «won’t ruin your battery» doesn’t mean it has no effect. Batteries naturally degrade with age and use, and how you charge plays a role in how fast that happens. Keeping a phone perpetually at 100% can add extra stress on the battery, especially when paired with heat, which is the real enemy of longevity.

Understanding when this matters (and when it doesn’t) can help you make small changes to extend your phone’s lifespan.

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The science behind battery wear

Battery health isn’t just about how many times you charge your phone. It’s about how it manages voltage, temperature and maintenance. Lithium-ion batteries age fastest when they’re exposed to extreme levels: 0% and 100%.

Keeping them near full charge for long stretches puts additional voltage stress on the cathode and electrolyte. That’s why many devices use «trickle charging» or temporarily pause at 100%, topping up only when needed.

Still, the biggest threat isn’t overcharging — it’s heat. When your phone is plugged in and running demanding apps, it produces heat that accelerates chemical wear inside the battery. If you’re gaming, streaming or charging on a hot day, that extra warmth does far more harm than leaving the cable plugged in overnight.

Apple’s take

Apple’s battery guide describes lithium-ion batteries as «consumable components» that naturally lose capacity over time. To slow that decline, iPhones use Optimized Battery Charging, which learns your daily routine and pauses charging at about 80% until just before you typically unplug, reducing time spent at high voltage.

Apple also advises keeping devices between 0 to 35 degrees Celsius (32 to 95 degrees Fahrenheit) and removing certain cases while charging to improve heat dissipation. You can read more on Apple’s official battery support page.

What Samsung (and other Android makers) do

Samsung offers a similar feature called Battery Protect, found in One UI’s battery and device care settings. When enabled, it caps charging at 85%, which helps reduce stress during long charging sessions.

Other Android makers like Google, OnePlus and Xiaomi include comparable options — often called Adaptive Charging, Optimized Charging or Battery Care — that dynamically slow power delivery or limit charge based on your habits. These systems make it safe to leave your phone plugged in for extended periods without fear of overcharging.

When constant charging can hurt

Even with these safeguards, some conditions can accelerate battery wear. As mentioned before, the most common culprit is high temperature. Even for a short period of time, leaving your phone charging in direct sunlight, in a car or under a pillow can push temperatures into unsafe zones.

Heavy use while charging, like gaming or 4K video editing, can also cause temperature spikes that degrade the battery faster. And cheap, uncertified cables or adapters may deliver unstable current that stresses cells. If your battery is already several years old, it’s naturally more sensitive to this kind of strain.

How to charge smarter

You don’t need to overhaul your habits but a few tweaks can help your battery age gracefully.

Start by turning on your phone’s built-in optimization tools: Optimized Battery Charging on iPhones, Battery Protect on Samsung devices and Adaptive Charging on Google Pixels. These systems learn your routine and adjust charging speed so your phone isn’t sitting at 100% all night.

Keep your phone cool while charging. According to Apple, phone batteries perform best between 62 and 72 degrees Fahrenheit (16 to 22 degrees Celsius). If your phone feels hot, remove its case or move it to a better-ventilated or shaded spot. Avoid tossing it under a pillow or too close to other electronics, like your laptop, and skip wireless chargers that trap heat overnight.

Use quality chargers and cables from your phone’s manufacturer or trusted brands. Those cheap «fast-charge» kits you find online often deliver inconsistent current, which can cause long-term issues.

Finally, don’t obsess over topping off. It’s perfectly fine to plug in your phone during the day for short bursts. Lithium-ion batteries actually prefer frequent, shallow charges rather than deep, full cycles. You don’t need to keep it between 20% and 80% all the time, but just avoid extremes when possible.

The bottom line

Keeping your phone plugged in overnight or on your desk all day won’t destroy its battery. That’s a leftover myth from a different era of tech. Modern phones are smart enough to protect themselves, and features like Optimized Battery Charging or Battery Protect do most of the heavy lifting for you.

Still, no battery lasts forever. The best way to slow the inevitable is to manage heat, use quality chargers and let your phone’s software do its job. Think of it less as «babying» your battery and more as charging with intention. A few mindful habits today can keep your phone running strong for years.

Technologies

Today’s NYT Mini Crossword Answers for Thursday, Jan. 8

Here are the answers for The New York Times Mini Crossword for Jan. 8.

Looking for the most recent Mini Crossword answer? Click here for today’s Mini Crossword hints, as well as our daily answers and hints for The New York Times Wordle, Strands, Connections and Connections: Sports Edition puzzles.

Need some help with today’s Mini Crossword? I found 6-Across to be especially tricky. Read on for all the answers. And if you could use some hints and guidance for daily solving, check out our Mini Crossword tips.

If you’re looking for today’s Wordle, Connections, Connections: Sports Edition and Strands answers, you can visit CNET’s NYT puzzle hints page.

Read more: Tips and Tricks for Solving The New York Times Mini Crossword

Let’s get to those Mini Crossword clues and answers.

Mini across clues and answers

1A clue: Donate
Answer: GIVE

5A clue: Piece of equipment in curling or Quidditch
Answer: BROOM

6A clue: Tidbit of information
Answer: DATUM

7A clue: Prone to daydreaming
Answer: SPACY

8A clue: Athletic shorts fabric
Answer: MESH

Mini down clues and answers

1D clue: Flavor of a purple lollipop
Answer: GRAPE

2D clue: Greek letter I’s
Answer: IOTAS

3D clue: Go to bat (for)
Answer: VOUCH

4D clue: Award with Daytime and Primetime categories
Answer: EMMY

5D clue: Erotic practice in «Fifty Shades of Grey,» for short
Answer: BDSM

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Technologies

New Foldable Phones Are Already Shaking Up the 2026 Smartphone Market

Commentary: Company announcements, analyst data and rumors of a foldable iPhone all point to an ambitious year for this still-young category.

What used to be a niche phone design is starting to flex its way into the mainstream. Foldable phones, which incorporate two or three panels that open into tablet configurations or condense down into compact sizes, are finding their audience. At CES 2026, for instance, Motorola announced its entry into with the book-style Razr Fold and Samsung showed off its Galaxy Z TriFold. Just as important, overall the category is seeing double-digit growth forecasts in 2026.

According to a December report from market research company IDC, global foldable phone shipments were expected to grow 10% in 2025 compared to 2024. And that number will continue to grow in 2026, with an expected 30% year-on-year jump, thanks to rumors of an upcoming foldable iPhone from Apple. And even though Samsung’s Flip and Fold phones have been around for years, the company’s newer TriFold and rumored «Wide Fold» have me hyped for what’s to come in 2026.

On the other hand, Huawei has led the way with innovative products, including its own trifold that beat Samsung to the category — the Huawei Mate XT — as well as a one-of-a-kind wide-screen flip phone, the Huawei Pura X. It dominated China’s foldable phones market with a massive 68.9% market share in the third quarter of 2025, according to a report from IDC (via MyDrivers). This is huge for a single brand in any market, especially when a niche category like foldables has several competitors (Oppo, Vivo, Xiaomi and more).

These new foldable phone styles, along with the rumored iPhone Fold from Apple — which is said to have a passport-size design — could mean we’ll see four different types of foldable phones by 2026, giving people more options for compact devices that unfold into larger screens.

The four kinds of foldable phones to expect in 2026

So far, the most popular foldable phones have been book-style (like the Galaxy Z Fold 7) and flip phones (like the Motorola Razr). While the former is a phone that unfolds into a mini-tablet, the latter folds into a more pocketable design. Both designs have their benefits, but if rumors are true, there are more ways to build a folding phone.

2026 will see two new designs in the category, and one of them has already been launched in several markets. Here’s why I think all these new foldable phones will have an audience.

Flip phones

The Galaxy Z Flip 7 and Motorola Razr lineups are built for those who want a compact phone without compromising on screen size. Not everyone has massive pockets in their jeans but that doesn’t mean they need to settle for a smaller screen. These flip phones are designed to be more pocketable while also offering the same 6.9-inch display as a regular slab phone.

Book-style foldables

The Samsung Galaxy Z Fold 7, Google Pixel 10 Pro Fold, Oppo Find N5 and Honor Magic V5 are all book-style foldables, which unfold to a mini-tablet. I like this design because I love browsing the web and reading on my phone and the squarish aspect ratio when unfolded makes it an excellent e-reader.

Recent developments in battery tech (silicon-carbon anode batteries) and hinge design have allowed manufacturers to shrink the crease depth and overall thickness to make them almost as slim as regular slab phones. These phones typically have big screens that aren’t ideal for videos, due to thick letterboxing. But they can be propped up by themselves, so you don’t need an external kickstand to watch 21:9 or 16:9 videos.

Book-style foldable phones are made for those of us who want to be more productive on a phone without needing a separate device.

The trifolds

This is the most versatile foldable phone design as of now and its best examples include the recently launched Samsung Galaxy Z TriFold and the Huawei Mate XT. However, not all trifolds are designed the same.

The Huawei trifold is the most versatile phone I’ve ever used, allowing me to use it as a phone, a mini tablet and a wide-screen 16:11 tablet for productivity and media consumption. It’s a true all-in-one device that delivers everything in a portable design.

By comparison, the Galaxy Z Trifold gives you a wide-screen 10-inch tablet that fits in your pocket and can also be used as a phone. It doesn’t offer a mini-tablet mode — you can use it either folded as a phone or fully unfolded — but Samsung’s trifold is designed as a productivity and media powerhouse. It’s essentially a flagship Galaxy Tab S-style device that fits inside your pocket.

Widescreen foldables

The Huawei Pura X is the best example of a wide-screen foldable so far. While some might argue that the first-generation Oppo Find N and Google Pixel Fold could fit under this category, their inner screens were also squarish (8.4:9 on the Oppo phone and 5:6 on the Pixel Fold); they were smaller book-style foldables.

In contrast, the Pura X has a 6.3-inch display with a wider 16:10 aspect ratio, which makes it an ideal screen for reading and watching videos. I used the phone recently for a few days and it’s the best combination of pockatability and versatility. You can watch videos with minimal letterboxing (thick black borders on top and bottom) on its 16:10 screen or use it like an e-reader in vertical orientation. And for the times when you need to snap some selfies using the rear cameras, you get a decent viewfinder in the form of a big cover screen — without making the phone unwieldy like book-style foldables.

Apple is rumored to adopt this approach with its upcoming iPhone Fold, but with a bigger cover screen. And Samsung is said to be developing a similar «Wide Fold» that’ll give you a 4:3 inner screen, too. According to a report from ETnews, this new Samsung foldable could have a 5.4-inch cover screen and support 25-watt wireless charging.

If the Korean company launches it alongside a presumed Galaxy Z Fold 8 and Flip 8, potentially in July 2026, it would launch ahead of Apple’s rumored foldable, which is presumed to launch in the fall.

While these foldable phones will likely be expensive — especially the newer trifold and wide fold shapes — they’re bringing a lot of new competition to a phone market that’s otherwise dominated by the candy bar shape. As we move into 2026, I’m looking forward to having multiple size, design and functionality options, much like we do with traditional phones.

Technologies

Speediance Unveils New Compact Resistance Trainer and Wearable

Speediance is aiming to make strength training more portable with a wearable unveiled at CES.

Speediance unveiled its new Gym Nano and Speediance Strap products this week at CES 2026. The smart fitness equipment manufacturer, which previously developed its own smart home gym, the Gym Monster 2, designed the Gym Nano and Speediance Strap to complement its current equipment ecosystem.

«Rather than developing products in isolation, we’re building a comprehensive training and health ecosystem that adapts to users’ real lives and empowers better decision-making over time,» Speediance founder and CEO Liu Tao said in a statement.

Speediance used the consumer tech expo in Las Vegas to demonstrate the Gym Nano, a portable, motor-driven cable resistance training system designed to occupy minimal space for those who prefer to work out at home. The strap is a prototype wearable device designed to read your health data and provide training recommendations based on this insight.

CNET previously tested Speediance’s VeloNix AI Smart Bike and named it the best AI-powered exercise bike.

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Gym Nano

The Gym Nano is a compact digital cable resistance machine trainer that fits any space and delivers full-body workouts. It’s meant to make strength training at home easier if you have limited space and can’t commit to larger home gym equipment.

The Gym Nano offers up to 220 pounds of resistance through adjustable 1-pound increments. It also has five dynamic weight modes: Eccentric, Chain, Standard, Fixed Speed and Sled.

Speediance Strap

The strap can be used for both endurance and strength training activities and recognizes various types of exercises, movement patterns, training volume and other insights that can help you learn how well your body is responding to your training.

The Speediance Strap is a screen-free wearable that collects data related to your sleep, training and core body temperature. It then uploads and shares this data to the Speediance Wellness Plus app, where it makes suggestions for your daily training and recovery based on this information. Similar to other wearables, the Speediance Strap assesses your readiness each day and can detect stress factors to determine if you should focus more on recovery on that day.

«With Speediance Strap, we are exploring how wearable data can function as part of a decision-support layer within a connected fitness system, rather than existing as isolated metrics,» Tao said in a statement.

Additionally, everyday insights (like core and recovery data) will be free to you unless you want to upgrade to the Wellness Plus access, which will come at an additional cost to receive long-term insights and AI planning.

It’s unclear when the Gym Nano will be available for purchase, but the Speediance Strap is expected to launch through a Kickstarter campaign in spring 2026.