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iPhone charge overnight is it safe?

Hi I’m just wondering if it safe to charge iPhone overnight? It was fully charged 100% at 10pm until 3am it stays at 100% is it safe for the battery? Optimize battery was on, I thought it will not surpass charge 80% and will charge again to 100%?

iPhone 11, iOS 15

Posted on Jan 19, 2022 11:44 AM

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Posted on Jan 19, 2022 1:39 PM

It won't hurt anything -- many, many people left their phone to charge all night every night for years before the optimized option was made available.


Note that after you turn the optimize option on, it takes awhile for the iPhone to learn when you normally unplug your phone in the morning. While it is learning, it will charge to 100% rather than 80%. See the information in About Optimized Battery Charging on your iPhone - Apple Support including the following:


When the feature is enabled, your iPhone will delay charging past 80% in certain situations. Your iPhone uses on-device machine learning to learn your daily charging routine so that Optimized Battery Charging activates only when your iPhone predicts it will be connected to a charger for an extended period of time. The algorithm aims to ensure that your iPhone is still fully charged when unplugged.

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Question marked as Best reply

Jan 19, 2022 1:39 PM in response to phoenix140

It won't hurt anything -- many, many people left their phone to charge all night every night for years before the optimized option was made available.


Note that after you turn the optimize option on, it takes awhile for the iPhone to learn when you normally unplug your phone in the morning. While it is learning, it will charge to 100% rather than 80%. See the information in About Optimized Battery Charging on your iPhone - Apple Support including the following:


When the feature is enabled, your iPhone will delay charging past 80% in certain situations. Your iPhone uses on-device machine learning to learn your daily charging routine so that Optimized Battery Charging activates only when your iPhone predicts it will be connected to a charger for an extended period of time. The algorithm aims to ensure that your iPhone is still fully charged when unplugged.

Jan 19, 2022 2:44 PM in response to phoenix140

There's nothing particular bad about it being at 100%. There are some theoretical benefits to delaying the time that it spends between 80-100%, but if it doesn't do it, that's not really an issue.


Apple's rated typical longevity of 80% battery health after 500 cycles has been around even before Apple had optimized charging available. But it's something that may have small benefits for battery longevity.

iPhone charge overnight is it safe?

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