The S8/S8+ does not fast charge when the screen is on

[LineKill]

It will only fast charge when the screen is off, not if you are using it or even if the screen is on. If you are in a hurry and want to do a quick charge, make sure you are not using it. Does this matter to you?

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

Phandroid
http://phandroid.com/2017/05/11/samsung-galaxy-s8-plus-wont-fast-charge-problems/

 

[Tim1954]

That would prevent overloading the charger, it's trying to fast charge the battery on top of lighting up the screen which usually means something is running....

 

[LineKill]

That would prevent overloading the charger, it's trying to fast charge the battery on top of lighting up the screen which usually means something is running....

It is a limitation of Quick Charge 2.0. Quick Charge 4.0 does not have this limitation and also provides a faster charge.

Edit: Apparently it is Samsung's Adaptive Fast Charge technology, which is Samsung's version of Quick Charge 2.0, that has the limitation and not a limitation of Quick Charge 2.0. When a test was done on the ZTE Blade V8 Pro, which features a similarly sized battery and Quick Charge 2.0, it took an 1hr 32min compared to the S8 which took 2hrs 51min to charge while playing a YouTube video the entire time.

 

[dejanh]

Ha, this explains why I found the S8+ to not charge any faster than my iPhone 7 Plus, in fact sometimes slower than the iPhone. Good info and just wow Samsung. Quite a fail.

 

[LineKill]

Ha, this explains why I found the S8+ to not charge any faster than my iPhone 7 Plus, in fact sometimes slower than the iPhone. Good info and just wow Samsung. Quite a fail.

It still displays a fast charging notification even when it is not fast charging. It takes almost twice as long to charge when the screen is on.

 

[sweetypie31]

When fast charging wasn't a thing didn't charging slow down anyway if you were using the phone?At least for me my charging always took a little longer if I used the phone while trying to charge it.

 

[sparkeater79]

Whoops

 

[sparkeater79]

When fast charging wasn't a thing didn't charging slow down anyway if you were using the phone?At least for me my charging always took a little longer if I used the phone while trying to charge it.

Basically yes. Maybe more so the fact that the battery was being drained at the same time it was being charged. Makes sense it would take longer to charge in this senario.

 

[dejanh]

When fast charging wasn't a thing didn't charging slow down anyway if you were using the phone?At least for me my charging always took a little longer if I used the phone while trying to charge it.

Yeah, indeed. I guess then that in some cases it makes sense to use a high amperage charger then with the S8+ that is not QC compatible.

 

[ThrottleJohnny]

When fast charging wasn't a thing didn't charging slow down anyway if you were using the phone?At least for me my charging always took a little longer if I used the phone while trying to charge it.

It also makes Samsung phones very warm and even hot. I don't think they wanted to fool around with that this go round.

As a result, the S8 stays relatively cool, has great battery life which should sustain itself much longer than past phones. I don't see this as a fail...at all.

 

[furiousyellow]

Does this also apply when you have the Always On display enabled?

 

[Jaycemiskel]

Yeah, indeed. I guess then that in some cases it makes sense to use a high amperage charger then with the S8+ that is not QC compatible.

Yeah, I think that's what I'm going to do in my car. There was a post in another thread on here that determined that it charged faster with the screen on with a non quick charge charger.

Does this also apply when you have the Always On display enabled?

No, AOD should charge at a normal quick charge rate.

 

[sweetypie31]

My original statement was kind of in reference to the person who said it was a fail on Samsung's part. This situation isn't new in phones so how is it a fail?