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You've been charging your smartphone wrong

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  • Leaving your phone plugged in after it reaches 100% could be damaging the battery.
  • You should plug your phone in whenever you can and charge it in short bursts, which could help the battery perform optimally for longer.
  • Don't let your phone overheat while charging. Remove the case if it insulates heat while your phone charges.


Yes, we know. Our smartphone batteries are bad because they barely last a day.

But it's partially our fault because we've been charging them wrong this whole time. 

Many of us have an ingrained notion that charging our smartphones in small bursts will cause long-term damage to their batteries, and that it's better to charge them when they're close to dead.

But we couldn't be more wrong.

If fact, a site from battery company Cadex called Battery University details how the lithium-ion batteries in our smartphones are sensitive to their own versions of "stress." And, like for humans, extended stress could be damaging your smartphone battery's long-term lifespan. 

If you want to keep your smartphone battery in top condition and go about your day without worrying about battery life, you need to change a few things.

Don't keep it plugged in when it's fully charged

According to Battery University, leaving your phone plugged in when it's fully charged, like you might overnight, is bad for the battery in the long run.

Once your smartphone has reached 100% charge, it gets "trickle charges" to keep it at 100% while plugged in. It keeps the battery in a high-stress, high-tension state, which wears down the chemistry within.

Battery University goes into a bunch of scientific detail explaining why, but it also sums it nicely: "When fully charged, remove the battery" from its charging device. "This is like relaxing the muscles after strenuous exercise." You too would be pretty miserable if you worked out nonstop for hours and hours.

phones 3x4
The batteries in these phones get stressed out, too.  Skye Gould/Tech Insider

In fact, try not to charge it to 100%

At least when you don't have to.

According to Battery University, "Li-ion does not need to be fully charged, nor is it desirable to do so. In fact, it is better not to fully charge, because a high voltage stresses the battery" and wears it away in the long run. 

That might seem counterintuitive if you're trying to keep your smartphone charged all day, but just plug it in whenever you can during the day, and you'll be fine. 

battery shot with gun bullet holes still working
Don't shoot your smartphone batteries, either.  24M

Plug in your phone whenever you can

It turns out that the batteries in our smartphones are much happier if you charge them occasionally throughout the day instead of plugging them in for a big charging session when they're empty.

Charging your phone when it loses 10% of its charge would be the best-case scenario, according to Battery University. Obviously, that's not practical for most people, so just plug in your smartphone whenever you can. It's fine to plug and unplug it multiple times a day.

Not only does this keep your smartphone's battery performing optimally for longer, but it also keeps it topped up throughout the day. 

Plus, periodic top-ups also let you use features you might not normally use because they hog your battery life, like location-based features that use your smartphone's GPS antenna.

Source: C2H 50H/YouTube

Keep it cool

Smartphone batteries are so sensitive to heat that Apple itself suggests you remove certain cases that insulate heat from your iPhone when you charge it. "If you notice that your device gets hot when you charge it, take it out of its case first." If you're out in the hot sun, keep your phone covered. It'll protect your battery's health.

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Antonio Villas-Boas was a consumer tech expert with over a decade of experience testing and reviewing smartphones, tablets, computers, smartwatches, and phone carriers.ExperienceAntonio joined the Business Insider team in 2015 as a tech reporter on the news desk and moved to the service journalism team in 2020. During his time as Business Insider’s senior tech reporter, Antonio developed industry-leading battery-life tests for smartphones and tablets, and covered and reviewed hundreds (if not thousands) of products from major brands like Apple, Google, Samsung, and OnePlus since as far back as Samsung’s Galaxy S6, the original Apple Watch, and the very first Google Pixel. This decade-plus of experience has given him tremendous insights into what consumer tech truly stands the test of time and what will be irrelevant in just a few years' time (RIP The Pebble).Antonio is also an experienced deal hunter, surfacing the best discounts on phones, laptops, and smartwatches for readers during sale events like Prime Day, Black Friday, and Cyber Monday. Previously, Antonio was a consumer-electronics analyst at PCMag and ran his own blog. Why you can trust AntonioAntonio approaches all his reviews not only as a tech expert but as a consumer himself. He reads every word of fine print in the phone carrier plans he reviews, and is deeply skeptical of deals that promise you the latest iPhone model for free. (Spoiler: it might be “free,” but you could be stuck with it for three years.)He largely recommends less expensive and small-scale fixes to upgrade your existing tech before considering buying the latest and flashiest in new tech. Antonio believes his role as the go-to “tech guy” for his family and friends extends to his readers as well; he only recommends products that have stood up to the testing process.Scripps News, NewsNation, Fox 5 DC, NBC LX, and Rich DeMuro’s “Rich On Tech” radio show have requested his commentary and expertise. ExpertiseHis expertise includes:
  • Phones, including the iPhone, Google Pixel, and Samsung Galaxy models
  • Phone accessories, including charging cables, phone cases, and protection plans
  • Smartwatches, including the Apple Watch, Galaxy Watch, Pixel Watch
  • Mobile carrier plans, including major carriers and MVNOs
  • Tablets, including iPads and Galaxy Tabs
  • Laptops and computers, including MacBooks and Windows models
  • Computer accessories, including mice, keyboards, and monitors
EducationAntonio graduated from Colgate University in 2009 with a bachelor's degree in history.Outside of workBesides testing tech products, Antonio is also a full time dad to two young kids. His ideal day would be spent on a lake in the Adirondacks.Learn more about how our team of experts tests and reviews products at Insider here.Learn more about how we test tech and electronics.