Does charging your phone overnight kill the battery?


No, your phone is designed to reach 100 percent. Once it does, the charger stops charging.


Isidor Buchmann- President/Founder/CEO at Cadex Electronics & author of

"How to Prolong Lithium-based Batteries"- Battery University

Fei Lin- Professor in Virginia Tech's Department of Physics




It's an argument couples will continue to have: does charging your phone overnight kill the battery?

Go online and search "charging phone overnight," you'll get 101 articles and leave with 102 questions.

Verify exists to answer questions directly from viewers about the stuff you read on social media. So when a viewer from McLean,Va. asked us, we went straight to the experts to find out whether overnight charging is a smartphone sin.

"Absolutely not," Isodor Buchmann, CEO and Founder of Cadex Electonics said. "Your phone is designed to be fully charged and then the charger turns off and the device sits there until it's used."

Buchmann runs diagnostics on batteries and said the lithium-ion batteries in smartphones is the "best technology that we have." That's because they're small, portable and have tremendous durability.

"You can pack much more energy in a small volume, compared to other kinds of batteries," Fei Lin, battery expert at Virginia Tech explained. "The battery operation in smartphones we have today...usually have a very nice battery management system."

That means smart phones are really smart. They not only know how long to charge your cell, but charges your phone at different speeds as it approaches full.


Even though your phone is designed to be completely juiced-up, Buchmann, who also created Battery University, an online-education tool for engineers and battery enthusiasts, said if you want to be kind to your phone, consider charging your phone once it hits 20 percent up to 80 percent.

That's the sweet spot. Why?

Most phones can charge "like-new" for 300-500 full charges, or cycles. That's going from 0 to 100 percent, 300 times. Apple claims their phone batteries perform like-new for 500 cycles.


So if you charge your phone from 20 percent to 80 percent, you've used up 6/10 of a cycle instead of a full one. Buchmann claims doing this can help your battery perform like-new for longer.

Still, we can verify, Buchmann said charging overnight is fine.

No battery is made to last forever, he calls it, "built-in obsolesce." Manufacturers know you'll buy a new phone in two or three years when a new model will come out, so they don't bother extending your battery's shelf life, Buchmann said.

So what is a smartphone sin?

Letting your phone get too hot. Sitting out on a 95 degree day, with your phone in direct sunlight can cause catastrophic, permanent damage to your juice pack.


Help our journalists VERIFY the news. Do you know someone else we should interview for this story? Did we miss anything in our reporting? Is there another story you'd like us to VERIFY? Click here.