A note to all Galaxy S8 users: fast charging only works while the screen is off

These days, a smartphone having some sort of fast charging solution has become the norm, not the exception, so most people would be excused for forgetting about the feature. So this is a friendly reminder that the S8 features the exact same technology as its predecessors, the S6 and S7, did before it. Samsung Adaptive Fast Charge, which is really just another name for Qualcomm's Quick Charge 2.0, still does its job as well as it did a couple of years ago, of course, but it does so with a small limitation: you can't use it while your device's screen is on.

Call it a first world problem if you will, but it's still kind of a bummer users of Samsung's most expensive flagship ever are stuck using flawed, years-old technology while better alternatives exist. In fact, Qualcomm's Quick Charge 4.0 sheds this limitation while also offering faster speeds as well. And the Snapdragon 835, which powers the US version of the device, supports 4.0 just fine, but since the international version with its home-grown Exynos 8895 chipset doesn't, Samsung seems to have chosen not to further fragment its user base.

What's most unfortunate here, however, is that the company seems to have either forgotten about this limitation of Adaptive Fast Charging, or is trying to cover it up – there seems to be no mention of it in both the user guide and the official support pages (which is the case with both the S6 and S7), and, ironically, the S8's user interface constantly displays a fast charging notification when a compatible charger is plugged in, despite this not at all being the case while the screen is on.

Not that big of a deal, right? Except, as Phandroid reports in its tests, the difference in charging times is nearly twofold, going from 1 hour and 37 minutes with the screen off to 2 hours and 51 minutes with it on. So Galaxy S8 users who need their phone charged in a pinch should make sure not to actually use it while it's plugged in.

source: Phandroid via SamMobile

Related phones

Galaxy S8
  • Display 5.8" 1440 x 2960 pixels
  • Camera 12 MP / 8 MP front
  • Processor Qualcomm Snapdragon 835, Octa-core, 2350 MHz
  • Storage 64 GB + microSDXC
  • Battery 3000 mAh(30h talk time)
Galaxy S8+
  • Display 6.2" 1440 x 2960 pixels
  • Camera 12 MP / 8 MP front
  • Processor Qualcomm Snapdragon 835, Octa-core, 2450 MHz
  • Storage 64 GB + microSDXC
  • Battery 3500 mAh(24h 3G talk time)



1. Bankz

Posts: 2550; Member since: Apr 08, 2016

A new day, a new quirk. Smh.

4. Tyrion_Lannister unregistered

It's not a quirk, it's been since 2-3 year on every phone with Qualcomm quick charge phone. That's why dash charge or USB PD are praised so much, and that's also why Qualcomm quick charge 4.0 adopts USB PD.

26. ph00ny

Posts: 2074; Member since: May 26, 2011

That is odd. Note 5 (exynos) does fast charge while being plugged in and actively used.

40. L0n3n1nja

Posts: 1600; Member since: Jul 12, 2016

It displays fast charging but it doesn't charge as fast.

42. michaelny2001

Posts: 354; Member since: Aug 01, 2012

um... no. This is stupid of Samsung. How come my OP3 chargers quickly while i watch a movie or play a game? if Oneplus can do it, so should Samsung. My Op3 uses Sd820. So no excuse. I wanted to see Samsung flourish but they keep messing up.

6. Cyberchum

Posts: 1127; Member since: Oct 24, 2012

And you know that it's a quirk, how?!

11. maherk

Posts: 7049; Member since: Feb 10, 2012

Smh or more like jumping out of joy? Because you're usually enthusiastic about any negative article regarding Samsung. Anyways, this is another lame article by PA that brings nothing new to the table. Samsung has disabled fast charging while the screen is on for years now, as it'll leave the phone extremely hot if it was enabled. Will wait now to the next article that shows how Apple disabled fast charging for the iPhones when the screen is on...oh wait!!

23. Iodine

Posts: 1514; Member since: Jun 19, 2014

Once more. iPhone + 12W = faster charging, even in heavy use, not much excess heat at all. Btw, how can Apple disable so called fast charging if... it doesn't have fast charging ? Or you think it does ?

24. maherk

Posts: 7049; Member since: Feb 10, 2012

Look up for the definition of sarcasm ;)

29. willard12 unregistered

"Btw, how can Apple disable so called fast charging if... it doesn't have fast charging ?" You really walked right into that one.

37. andrewkb

Posts: 24; Member since: Jan 04, 2016

exynos version only,

2. AmashAziz

Posts: 2934; Member since: Jun 30, 2014

It's so that the battery doesn't heat up and explode!

16. submar

Posts: 713; Member since: Sep 19, 2014

Go back to your pen.

3. Tyrion_Lannister unregistered

I don't think any phone except the oneplus 3/3T supports fast charging while screen on. Maybe the pixel too. It's because high voltage-low current fast charging(QC 2.0/3.0) heats the battery much more than low voltage-high current fast charging(QC 4.0/dash charge/USB PD). S8/S8+ also support USB-PD(at least the exynos, not sure about SD) with upto 5V, 3A. Would like to see how that works with screen on, since that shouldn't heat the battery.

5. Talhamid

Posts: 61; Member since: Jun 13, 2009

First of all, very few people charge their phones while using it. Secondly, have you, iPhoneArena, EVER considered or reported how long iPhone 7 plus takes to charge? Have you held comparisons (which you are so fond of)? Have you ever even mentioned it in a review of an Apple product that while Samsung is using OLD fast charging tech, Apple is using NO fast charging tech? While you happily compare current Android phones with EXPECTED/RUMOURED device from Apple, Did you care to mention in this piece of investigative journalism that an s8 with screen on STILL takes less time to charge than an iPhone with the screen off?

10. hansip87

Posts: 231; Member since: Nov 10, 2015

the reality is, many people (esp women) likes to chat/play farming games while it's on charging..

21. Iodine

Posts: 1514; Member since: Jun 19, 2014

Once more: iPhone (6 and up) are friends with 12W (or 10W) charger. It charges faster and that gets more prononced as you start to use your iPhone, because it will simply draw more power for the phone. It's not called Apple slicer turbo plus 4.284 fast charge tech, but guess what - it works and it works well - and I use it and like it.

30. MrElectrifyer

Posts: 3960; Member since: Oct 21, 2014

Then when it explodes like this iPhone did while being charged with the toyPad charger ( https://is.gd/rt3kxg ), you same sheeple would be bahing "they didn't use the original charger, it's their fault"...typical hypocrites.

34. RoryBreaker

Posts: 290; Member since: Oct 11, 2015

How can you qualify "very few people?" I for one use the phone quite often while it's charging. It was the only way to make sure the battery was topped off before I had to be out without access to a charger.

7. thetruthhasbeenspoken

Posts: 83; Member since: May 02, 2017

Can iphonearena make their anti-Samsung propagandas less obvious. How long does an iphone charge? Why isn't that have an article.

8. sachouba

Posts: 267; Member since: Jun 08, 2014

Samsung has been doing that since the Galaxy S4... Don't pretend this is some breakthrough.

9. ibend

Posts: 6747; Member since: Sep 30, 2014

at least it still work with always-on-screen, and that's technically not screen off.. but I use wireless charging 100% of time, so I don't care..

12. Ordinary

Posts: 2454; Member since: Apr 23, 2015

You can change it with custom kernel but whats the point?

13. darkkjedii

Posts: 31748; Member since: Feb 05, 2011

I normally don't call out the PA authors, as I respect the work they do, but it seems they really have it in for the S8. This is a phenomenal device, and all they really have been doing is ripping it apart. I for one, have had no actuall issues at all with mine, battery life is the best I've ever had on a phone, it never lags, is super fast and smooth, and stunning to look at. All this nit picking is for the birds. That phone is a tank, and performs awesomely. It has me barely even thinking about, or using my 7 Plus, and I love that device too. It's just that good. PA give us an article on what you guys actually like about the S8.

17. joeytaylor

Posts: 957; Member since: Feb 28, 2015

They must be scared of the phone

33. darkkjedii

Posts: 31748; Member since: Feb 05, 2011

@joey. Exactly, cause it's just that good.

28. willard12 unregistered

You know that Phonearena is really reaching and grasping at straws when they start failing the Darkkjedii test. Adaptive fast charging doesn't work with the screen on......maybe PA should request an FBI investigation over this Breaking News that the Redditors or XDA people probably haven't even complained about. But, everyone knew it was a matter of time until they started seeking their personal vendettas.

14. Zack_2014

Posts: 677; Member since: Mar 25, 2014

I turn off the fast charging anyways lol

15. shamrock_sean

Posts: 37; Member since: Apr 27, 2017

My Galaxy A5 2017 charges fast when screen is on

18. palmguy

Posts: 988; Member since: Mar 22, 2011

My Moto X Pure Edition charges fast with the screen on.

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