iPhone 16 Battery Draining Overnight After iOS 26 / 26.1 Update

Apple recommends keeping your phone on a charger overnight.

There is no need to turn off WiFi, cellular, & Bluetooth if you follow Apple's recommendation. And your phone will be fully charged in the morning.

In addition, your phone cannot back up or curate its photos without wifi and on charge.

10% is quite modest, 20% is more likely, but only if you accidentally forgot to charge it.

Kurtosis12 is quite right.

Now if it lost more than 3% off charge and powered off for the night, that's quite another problem.

Charge your phone all night, every night and make sure to update to iOS 26.2. A drop of 10% overnight does not indicate a problem. Some apps will also perform additional background activities as noted at Settings > Battery that continue to use the battery even when the app is not opened.

rakib2001 wrote:

@Kurtosis12, I used to charge my iPhone 13 overnight. One day, I woke up and found that the display had started flickering and eventually turned yellowish-green. Later, when I took it to the repair center, they confirmed that it occurred due to charging overnight, which caused overheating and damaged the display IC. That is why I avoid charging overnight.

You simply got some bad information. Users are not experiencing display failures due to charging their devices overnight.

rakib2001 wrote:

Also, the phone’s battery health is still at 71%, which suggests the device is relatively new and the battery should not be behaving this poorly yet.

No! That suggests your battery needs to be replaced. That is recommended when it drops below 80%. I am surprised you are also not seeing Service Warnings in your battery settings.

rakib2001 wrote:

Sorry, that was a typo. The battery cycle count is 71 and the battery health is 100%. I also mentioned in the post that I bought it on October 15th. @Mac Jim ID

Whew! I would be have thought you would have been experiencing much more serious problems with a 71% Battery Health.

Your phone is still working when left overnight, charge it all night, every night.

rakib2001 wrote:

@Kurtosis12, I used to charge my iPhone 13 overnight. One day, I woke up and found that the display had started flickering and eventually turned yellowish-green. Later, when I took it to the repair center, they confirmed that it occurred due to charging overnight, which caused overheating and damaged the display IC. That is why I avoid charging overnight.

If ANY qualified technician told me that, I'd take my phone somewhere else. What they told you is simply wrong, but worse preposterous. Charging your phone at night while you sleep is what Apple recommends and what all of us senior members on this forum do EVERY night, ALL night. Not doing so is actually going to reduce the health of your battery faster, which I'm sure isn't what you want to happen.