Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

iPhone 8/Plus Does wireless charging iPhone 8 or X kill battery life or work slower than wired charging?

Starfyre

Starfyre

macrumors 68030
Original poster
Nov 7, 2010
2,905
1,136
When an iPhone 8 has been on a wireless charging pad for 7 hours, feels warm when picked off of the pad and only charged till 70 percent. Is this normal? Does the battery go bad easier with wireless charging? With leather case, which is less than 3mm thick, which shouldn’t interfere with the charging.
 
Wireless charging on the iPhoneX seems to be about equal to the default usb adapter ( 5w ).

My wireless charger ( Mophie ) fast charges at 7.5w, so it would be a little bit faster than the default setup. When charging from less than 50% it does indeed get warm, but no where near hot.
http://www.mophie.com/shop/wireless-charging-base

I am using the Apple leather case.

Wired charging via Apple's 29w and 87w USB power adapter does seem to degrade the battery a bit faster than default. This possible faster battery degradation may be due to higher than normal phone usage, thus the need for faster than default charging.
 
"Linus" says wireless charging helps extending battery life. I take it with a grain of salt.
The current situation is wireless charging is still slow compared to wired charging in many ways, and carrying a charging pad on the go is not feasible. Just imagine taping your phone on the pad and connect your pad to the power source.

But you say you have a case. That could impact device cooling while charging.
 
Anything that causes excess heat is bad. In my android experience, my phone got 5-10 degrees hotter on my wireless charger than wired.
 
  • Like
Reactions: fatlardo
I’ve been using an Anker power wave wireless charger which supports 7.5w quick charging and I haven’t noticed any difference in heat when compared to wired charging
 
Inductive charging is inherently less efficient than wired charging. That loss in efficiency is in the form of heat. And to bring that heat right underneath your iPhone?

I'd choose battery health over convenience, especially since I can't use the phone on wireless charging.
 
Starfyre said:
When an iPhone 8 has been on a wireless charging pad for 7 hours, feels warm when picked off of the pad and only charged till 70 percent. Is this normal? Does the battery go bad easier with wireless charging? With leather case, which is less than 3mm thick, which shouldn’t interfere with the charging.
Click to expand...

I don’t Believe if it feels ‘warm’ that’s anything to be of concern, especially for seven hours as you indicated, because it’s transferring energy in charging your battery. If there is anything uncomfortable to hold due to the heat, that can be an issue on its own. Also, be aware, when you charge your phone with a Leather case, it’s trapping heat, so that might be another reason why it feels warmer as well.
 
  • Like
Reactions: BigMcGuire
Heat could also be caused if the coils are not lined up properly, and only some of the electricity is flowing. Make sure the phone is centered on the charger both horizontally and vertically to ensure proper alignment.
 
Starfyre said:
When an iPhone 8 has been on a wireless charging pad for 7 hours, feels warm when picked off of the pad and only charged till 70 percent. Is this normal? Does the battery go bad easier with wireless charging? With leather case, which is less than 3mm thick, which shouldn’t interfere with the charging.
Click to expand...
I have an iPhone X that I charge on a (yes, Samsung) 9 watt wireless charger pad, with an Apple leather case on the phone. The iPhone 8, 8+ and X all support up to 7.5 watt wireless charging and it is faster than the standard setup of wired charging.

On long charges (when the phone is at or less than 20%), the phone does get quite warm sometimes which from what I understand can degrade the battery faster. So my rule of thumb is to try and charge it before I dip below 30%, or if it’s really low, let it cool down half way through the charge (take it off the charger for half an hour or so). This will help keep the damage to the battery from heat a little less.

That being said, don’t worry about your phones battery too much. After 2-3 years it’ll need to be replaced or you’ll have moved on to a new device. Not worth stressing out on it IMO, just enjoy the phone now.
 
  • Like
Reactions: 960design
BugeyeSTI said:
I’ve been using an Anker power wave wireless charger which supports 7.5w quick charging and I haven’t noticed any difference in heat when compared to wired charging
Click to expand...

I am also using that charger with my iPhone 8. It works great and does a complete charge in a couple hours - about the same time as when using the iPad Lightning charger. I really like it.

The efficiency (and charge time) will vary with the thickness of the case you are using. I'm using a fairly thin flexible plastic case.
 
colodane said:
I am also using that charger with my iPhone 8. It works great and does a complete charge in a couple hours - about the same time as when using the iPad Lightning charger. I really like it.

The efficiency (and charge time) will vary with the thickness of the case you are using. I'm using a fairly thin flexible plastic case.
Click to expand...
Just curious, does the blue led always stay on when the phone is on the charger or does yours shut off when fully charged? Mine stays on even after showing 100% and fully charged
 
BugeyeSTI said:
Just curious, does the blue led always stay on when the phone is on the charger or does yours shut off when fully charged? Mine stays on even after showing 100% and fully charged
Click to expand...

Yes, my blue light also stays on after the charge is complete.

By the way, others have complained that the light is too bright and distracting. I don't find that to be the case. Even though it is in my bedroom, it doesn't seem too bright. Also, the audible fan noise that others have mentioned has not been an issue here.
 
My phone (8+) is often a little warm after it charges, but this makes sense due to the resistance of the inductors used for the wireless charging. It shouldn’t get too warm though, this could be a problem in the wireless charger you’re using. The slow charging also indicates there is a problem with the voltage being supplied by the wireless charger
 
I leave my iPhone X on my wireless charger at work all day and use it when I need to and put it back so it’s always at 100% when at work
 
tonybarnaby said:
Anything that causes excess heat is bad. In my android experience, my phone got 5-10 degrees hotter on my wireless charger than wired.
Click to expand...
It’s not “bad” it’s the natural inefficiency of wireless charging. Warmth in electronics doesn’t harm a thing until you get to temperatures well above what would be comfortable to touch.
 
NT1440 said:
It’s not “bad” it’s the natural inefficiency of wireless charging. Warmth in electronics doesn’t harm a thing until you get to temperatures well above what would be comfortable to touch.
Click to expand...

If you listen to Dr. Jeff Dahn of Dalhousie University, the battery researcher who now works for Tesla, he has said temperature and state of charge are what kills batteries.

In his talks, he has suggested storing li-ion cells in the fridge is a good idea to prolong life.

Human temperature tolerance is a poor way to determine if something is harmful for electronics.
 
  • Like
Reactions: acorntoy
JPack said:
If you listen to Dr. Jeff Dahn of Dalhousie University, the battery researcher who now works for Tesla, he has said temperature and state of charge are what kills batteries.

In his talks, he has suggested storing li-ion cells in the fridge is a good idea to prolong life.

Human temperature tolerance is a poor way to determine if something is harmful for electronics.
Click to expand...
That’s great, a temperature under 100F isn’t going to a thing to an iPhone.
 
JPack said:
I'm not sure where this random number comes from.
Click to expand...
It’s the line where most people consider something “warm” to the touch, that’s the context of this thread.

Of course high temperatures are bad for batteries, but high temperatures to the human touch (the factor all “my device is warm/hot” threads are based on), is completely different from what would be considered “hot” for electronics.

I’m or disputing that professor, but there’s no way in hell he’s using human touch as the benchmark for what is considered too hot for batteries.

Does that make sense? I’m having a hard time finding another way to unpack the terms being used.
 
NT1440 said:
It’s not “bad” it’s the natural inefficiency of wireless charging. Warmth in electronics doesn’t harm a thing until you get to temperatures well above what would be comfortable to touch.
Click to expand...
Battery capacity loss begins at 86F according to sources I’ve read
 
NT1440 said:
Long term, or for the current charge?
Click to expand...
Long term battery longevity is affected when a lithium ion battery is above 86F. This is impossible to avoid, but it’s the reality of the technology. Batteries lose capacity mainly due to age, heat and excessive usage. Someone who keeps their phone on their dash mount while driving for Uber will destroy their battery way faster than someone who works in an office.
 
Interesting to see so many right and wrong points of view..... All integrated and aligned..... Not that I know all in's and outs of the subject. But I know that fast charging is comfortable when one is in a hurry. But is it good or bad...? There is a source to turn to in order to know all about batteries: The Battery University! (Not that they know al.... but they know more :)
One thing is for sure don't charge your battery under low temperature conditions. So never keep them in the fridge!

https://goo.gl/wpCSUX
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back