Phone charging at night.
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Smartphones have advanced a lot over the years, but they still basically last about a day on a charge. That means most of us are juicing up the battery all night while we sleep. Is that good for the battery?

Contrary to what you may think, battery technology has actually improved quite a bit. The problem is phones can also do a lot more now, meaning they require more power. The end result is bigger, better batteries that still need to be charged daily.

RELATED: 8 Tips for Saving Battery Life on Your iPhone

Information Changes

What makes this situation complicated is there’s a lot of contradicting information out there. Maybe you’ve heard that charging your phone overnight is bad. Maybe you heard it’s completely fine.

Some of this confusion is due to advancements in battery technology. Things that were true at one time are no longer true. That’s a natural part of learning more about how things work. So what’s the deal right now? Let’s dive in.

How Charging Works

Charging a smartphone and tablet.

The moral of this story is similar to other topics revolving around how to “properly” use gadgets. In most cases, the device was designed to handle whatever it is you’re worried about. For example, you don’t have to close apps on Android, it’s designed to handle multitasking for you.

Smartphones are designed with protections in place to keep the battery and other components inside safe. One thing that can do damage to phones is overheating, which is where a lot of the concern for charging overnight comes in.

Most phones will charge quickly when you first plug them in or place them on a wireless charger. This is so if you just need some extra juice in a hurry you don’t have to wait long. However, after a while, charging will slow down and stop entirely when it reaches 100%.

Of course, since it stops charging at 100%, the battery will slowly discharge. Once it drops to 99% again, it will sip a very small amount of power to go back up to 100%. That cycle repeats itself until you take it off the power. The phone is never being overcharged, but it is almost constantly charging.

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Advanced Protection

Battery image showing the first 80% is fast charge, final 20% is a trickle charge

You may have heard that keeping a battery charged between 20-80% is best. Apple and some Android manufacturers have introduced extra features to keep your phone in that range as much as possible.

Beginning with 2019’s iOS 13, iPhones have an “Optimized Battery Charging” feature. When enabled, the phone will stay around 80% for most of the night. An algorithm learns when you typically wake up and charges the device the rest of the way before that. You still start the day at 100%, but it wasn’t cycling between 100 and 99% all night.

Some Android devices have essentially the same feature. OnePlus calls it “Optimized Charging;” Google Pixel phones have “Adaptive Charging.” Samsung Galaxy devices take it a step further and allow you to cap the battery at 85% all the time.

If you charge your phone overnight, it’s a good idea to enable these features if you have them. It makes charging overnight slightly less problematic.

RELATED: How to Enable or Disable Optimized Battery Charging on Your iPhone

How Do We Define “Bad”?

A Pixel battery illustration.

With those protections in place, it’s very, very difficult for you to do any undue damage to your phone’s battery. However, batteries will degrade over time and there’s nothing anyone can do about that. It’s just a matter of how much are you helping that process along.

Charging cycles are what affect the lifespan of your battery. The more charging cycles it goes through, the more the battery degrades. This is why it’s best to keep your phone between 20-80% charge as much as possible.

RELATED: How to Check Your iPhone's Battery Health

That’s where charging overnight can speed up the battery degradation process. Cycling between 99-100% for several hours is sorta like flipping a light on and off. It’s not going to make the bulb explode into flames, but it’s also not particularly good for the bulb.

That’s the question we have to ask when it comes to charging batteries overnight. What exactly constitutes “bad” for the battery? Is your phone going to overheat and start on fire? No, there are protections in place to prevent that—as long as you use the correct equipment. Will it take some life off the battery? Yes, but it may not be noticeable to you.

RELATED: How to Check Battery Health on Android

Charge Overnight Without Damage

wireless charger
Nor Gal/Shutterstock

There are some things you can do to charge your phone overnight and mitigate some of the downsides. First and foremost, make sure the device has room to breathe. Overheating is a big concern, so give it room and don’t cover it up with anything.

The other big thing you can do is choose the correct charging equipment. Using the chargers provided with the device and those specifically designed for it is very important. Beyond that, you may consider avoiding “fast charging” during bedtime. Getting to 100% slower means spending less time in that 99-100% cycle.

Other than that, you kinda have to accept that batteries can’t last forever. Using your phone is degrading the battery. There’s no getting around that. There are some tips you can use to slow that degradation down, but most of us have no other convenient time to charge up our devices. Charging all our devices overnight is a part of life now.

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Profile Photo for Joe Fedewa Joe Fedewa
Joe Fedewa is a Staff Writer at How-To Geek. He has been covering consumer technology for over a decade and previously worked as Managing Editor at XDA-Developers. Joe loves all things technology and is also an avid DIYer at heart. He has written thousands of articles, hundreds of tutorials, and dozens of reviews.
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