Wireless Charging - Phone and Charger Hot

[DLCPhoto]

I have a brand new Verizon S21 Ultra 256gb, ordered from Verizon, and it came with a free EB-U1200 wireless charger.  I used it for the first time last night, placing the phone on the charger on my nightstand, keeping the phone on for emergencies.

In the morning, it was at 100% as expected, but both the Phone and Charger were fairly warm to hot, which I didn't expect.  I assumed that once the phone reached 100%, it would switch to a trickle charge state, which wouldn't generate much heat.

I have another older Samsung charger (EP-PG950), used with my prior Note 8, and neither the Note 8 nor the charger ever got noticeably warm.  I haven't tried this charger overnight with the S21 Ultra yet.

So this raises several questions:

1. Should the phone and charger be that warm when left overnight?
2. Is it detrimental to battery life and quality to routinely leave it on a charger (wireless or wired) overnight?
3. Currently, I have "Fast Charging," "Super fast charging" and "Fast wireless charging" all enabled - would disabling some or all of these be best for overnight charging, and would this eliminate the heat problem?

I've researched this, and inevitably find conflicting information on "best practice" in this regard, but am curious to see what knowledgeable members here think, perhaps specifically with regard to the S21 Ultra.

Thanks.

[LongHiker · Accepted solution]

@DLCPhoto Some suggestions:

• If you have a case, especially a thick case, more power is required to get through the case and it will be warmer than without the case. 
• If you disable "Fast wireless charging" then it will generate less heat. 

"Is it detrimental to battery life and quality to routinely leave it on a charger (wireless or wired) overnight"

This is like a religious discussion. You will have people post strong feelings on both side of the issue. In my experience, it doesn't matter. Do what is best for your lifestyle. 

[DLCPhoto]

Much appreciated, @LongHiker .

My case is actually on the thick side - ArmadilloTek Vanguard - very protective, and excellent buttons for Volume and Side, but does provide a bit of heft.

I'll turn off "Fast wireless charging" tonight and see how much difference it makes.  The case is too difficult to remove routinely, so that's not a practical option for me.

As for the "religious discussion" - that's definitely what I find, and why I almost hesitated to ask the question.  It is curious that something that should have a fairly definitive, objective answer, ends up being such a controversial topic!

[bill-e]

I used the ArmardilloTek  Vanguard case for 3 months without issue but I have a Bixby routine set to turn off Fast charging between 10pm and 7am every night.  This way if I need to fast charge during the day I can without having to turn things on and off.

[DLCPhoto]

I'll have to take a look at Bixby routines.  I've never really paid attention to Bixby with my Note 8, but this does sound interesting.  I am very much into Control4 Home Automation, so this would go right along with that.

[bill-e]

and my religion is that a hot battery ages faster than a cold one. 

[DLCPhoto]

It's hard to argue against the logic here - heat and electronics in general typically don't play together very well.

If my phone stays too warm, even with Fast Charging turned off, I think I may figure out a different routine for keeping my phone charged.

[DLCPhoto]

Just following up here: I turned off Fast Wireless Charging, and while the phone is still mildly warm by morning, it is much better than when it was enabled.  It takes quite a few hours to reach full charge, so there's significantly less time for 'over-charging' (if that's really an issue).  Hopefully this will provide a decent balance between practicality and battery life.

I also set it to turn on Do Not Disturb, and turn off AOD from 10:30 to 7:00 am, which works well for my schedule.

[DLCPhoto]

Another follow-up here:

I find it also convenient to auto-restart my phone overnight (I now have it set for 5:00 am), so it's always "fresh" when I get up.  The only problem is that when it reboots, the screen gets very bright as the Verizon logo and so forth are coming up.  This can wake me up, even though there's no sound since it's on 'Do Not Disturb.'

I assume there is no way to prevent the screen from turning on during the restart process, correct?

The other option is to place my phone face-down (the Armadillo case has a nice lip in front to protect the display, and which should also somewhat 'seal' it on the sides, to minimize light escape) to prevent it from lighting up the room during restart.  But this might also accentuate the heat problem, since the area in front of the screen would be somewhat of a dead-air space, with little to no ventilation.

Any thoughts on this?  Covering the phone with an opaque cloth or something would have the same potential issues with heat trapping.