iPhone X battery drained 100% overnight

First of all you having auto-brightness enabled won't automatically replicate the bug by itself. Logically speaking, millions of users have auto-brightness enabled and this is an issue that plagues thousands of Apple X owners, not everyone who has auto-brightness enabled. It's a combination of likely software or even hardware issues. In troubleshooting, it's an essential step to list the exact conditions and remedies attempted, and his mentioning that disabling auto-brightness an implication that it's "causing" the malfunction, but that it is possibly contributing to it, along with other factors.

Second it's never a good idea to plug in your phone for a charge when it's 100%. At the very base level it's bad for the environment to waste electricity, and although there are safeguards it's always possible to damage your any lithium-ion battery at 100 and 0%, shortening battery life. Especially if the battery is malfunctioning, has issues with charging, or has software issues reporting battery life and a half dozen other possibly related issues with any battery issue like this.

Third connecting to wi-fi nor iCloud backup is dependent on the battery being charged or the power cable plugged in. It is good that you try to have a routine for best practices with even simple things like charging your iphone but it is not necessary to be (over)charging a 100% iphone in order to have it back up or connected to wi-fi.

So Chris those are some answers to the questions you had, unrelated to the thread. As for the thread I had this issue with battery drain happen twice this past week. My original thought was that the screen lock bug (where the iphone does not engage screen lock after you change certain settings, including the setting for dead interval before lock in certain conditions) had left my phone's screen on over the weekend when I wasn't using/checking that phone but now that I see this thread I wonder....

Hard reset plus a sleep/wake seems to have at least for the moment fixed the screen lock failure and I don't notice any undue battery drain atm, will keep monitoring. FWIW I had auto-brightness up, all apps closed when the battery died

Hey Chris, I'm not really responding to "you" I am correcting/responding to some things posting in the thread. Everyone else is here to fix the battery bug, not "talk about Chris" so I hope you didn't take anything written personally, or to discuss which issues you personally have or do not have with your phone (unless you also have the issues detailed here as everyone else has). I'm sure anything like that is the furthest thing from anyone's mind.

As far as the battery, yes lithium-ion batteries do have a shut off circuit and yes they can waste electricity if plugged in due to trickle charging. A bunch of "best practices" were listed so I made it a point to emphasize that it's NOT a good practice ever to plug in a phone to charge if you know it's fully charged.

In theory a lithium-ion battery should never overcharge, it should not get drained quickly after engaging the autoshutoff, it should not typically get warm when charging. But in the real world these things all can happen. As I specifically stated, this is ESPECIALLY important when the battery itself is experiencing issues. If the battery is draining quickly or reporting the wrong charge, or having issues holding a charge these are all situations where you must assume that any of the above are possible. I could be a hardware issue or it could be a software issue, in which case overcharging could potentially even more dangerous.

Even in normal usage overcharging a battery or leaving it plugged in at 100% have in thousands of cases resulted in the battery overheating or even becoming dangerously hot. At minimum such issues with the battery can reduce battery life. Considering what this thread is about... battery issues... and what you posted about "best practices" do NOT plug in your battery when it's fully charged overnight just in some Thoreauian pursuit of "foolish consistency" there is 0 benefit and some (small) downside.

The screen lock bug is a known but unsolved issue, much like this one where the autolock feature of the iphone X or 8/8+ does not engage as designed. Meaning the phone stays on after the dead interval assigned to the phone. So if your phone is supposed to lock and engage sleep after 30 seconds (1 minute w/e) it does not dim and then lock at all. So the phone remains on until manually locked. Again you're a valuable contributor with active engagement on the forum but don't feel compelled to respond every time you yourself have not had an issue. Apple has sold over 1.2 billion phones, and most issues only affect a small percentage of users. It's ok to not have had an issue.

again everything in this post was first and foremost addressed to ALL users who might have experienced any of these issues and to clear up some bad information that might hard users.

Chris, thanks for your work on this forum. I am sure it has been helpful!

Hi

Go to apps store download Battery life it will test your battery condition.

Go to i books download ios 11 user guide &iPhone X guide both are free.

Cheers

Brian 🇬-1F1E7;

This is happening with my iPhone X also; unfortunately it’s not a one-off. Do Apple listen to these forums or is a genius appointment the best course of action. Two weeks and no resolution!

Oh look, some helpful feedback instead of smartass ‘advice’! Many thanks Sir!