How to Tell If You're Using a Slow iPhone Charger

[Hyperchaotic]

That's me — mine is slow charge overnight.

Yeah, I’ve been using the same “slow” 7.5W Qi charger since they first came out, I wonder if that’s why my batteries last 4years or more.

 

[Hyperchaotic]

It would be nice if iOS displayed the current charging speed (in watts) in the battery section of Settings. It would be a lot easier to make sure 3rd party chargers (and the cables) aren’t lying about their wattage.

That would be complicated as the BMS constantly changes the speed. If the battery is very low it’ll charge as low as 10% of max speed to begin with, then later set a constant current but ramp up voltage gradually, then maybe at 80% it’ll stabilize the voltage and start to reduce the current again. As watt=amps*volts there’s never a charging speed in watts a user can understand. It’s constantly changing and could also be regulated based on other parameters like battery temperature.

If you put max negotiated wattage then the user might get annoyed it doesn’t charge as fast as “stated”.

 

[Moukee]

In iOS 18, Apple has introduced a clever new way to identify if your iPhone charging setup is running at less than optimal speeds. The new feature appears directly in Settings, making it easy to spot when you're not getting the fastest possible charge.

Doesn’t seem so clever to me if it’s hidden in this screen. Just show the charging speed and remaining charging time on the lock screen already, like many other smartphones do.

 

[Oscar_440]

That's me — mine is slow charge overnight.

And your iPhone’s battery will probably last longer than others who do fast charging…
I don’t know why Apple colored in orange the slow charge periods. It’s clearly better for the battery 🤷🏼‍♂️. Fast charging should be in red instead.

 

[Reason077]

I deliberately use a slow 5W charger if I’m leaving the phone overnight or don’t need a quick charge. Charging slow is better for long-term battery health!

 

[uacd]

At this point Apple can make a non-removable warning on the lock screen “you are using slow charger” in bold red font to spook even more people who have 0 idea how charging actually works, then implement full 100W charging in iPhone 17. In a year they can expect more users to upgrade to 18 because their batteries will already be at 80% or below.

If Apple actually cared about users they would have long added the software switch “charge slowly”. But at this point they only care about how to downgrade the existing user’s hardware with poor and non-downgradeable software

 

[AF_APPLETALK]

If you want to get into nitty gritty..

Faster charging does create more heat and that is a fact. (Not saying it will cause damage -- if the term "damage" means degrading the device below it's advertised performance)

Engineers likely designed the device to reach an "acceptable" level of temperature that the battery can tolerate during fast charging. The term "tolerate" is important here.

Because batteries contain chemistries sensitive to heat, it will always impact the performance. That opens up a possibility that by not exposing the battery to fast charging it can extend the life of the battery beyond it's advertised life.

Well stated!

Agreed. i overnight charge my phones, the old 12W iPad chargers do a great job. and it's still labelled as a slow charger.

Yeah I'm doing the same - using a 12w adapter from a previous iPad with my 15 PM. It's a bit quicker than the 5w, but never makes my phone actually run hot. Perfect in-between.

 

[10anta]

I still don’t understand why Apple doesn’t offer charging by Smart Connector pins - it’s convenient, magnetically aligned, pseudo wired rather than wireless, and thus efficient and better for the battery. Apple could sell an official dock and other accessories.

 

[Jim Lahey]

Slow charging is FTW, and if it was detrimental to the battery then the phone simply wouldn't charge when connected to such a power supply. Still, great way to sell hundreds of millions of brand new power bricks to unsuspecting iPhone users rocking legacy USB-A chargers who will now think they're damaging their battery. The environment just called, it wants its Apple stickers back 🤦‍♂️

 

[Nclaire44]

To me, this orange indicator is really bad and misleading UI. I have a "slow" charger in my car (10w Belkin with magsafe), was surprised to see these orange bars and intuitively thought it was an indication of heat. To me, orange or red indicates heat.

Plus, slow charging is actually better for the battery, so this specific UI is very surprising coming from Apple. I get that they want us to fast charge, but they could adopt other color schemes (blue for slow? red for too hot?)

 

[svish]

Good article. The feature can turn out to be useful in certain situations.

 

[DaniTheFox]

I think you mean volts, not watts. Maybe. Not sure.

Apple’s 12W USB-A charger is 5.2V/2.4A.

As I understand, USB 1.1/2.0 requires only 500mA of power, resulting in a maximum output of 2.5W when powered by 5V. USB 3.0 (with a USB-A connector) mandates a minimum of 900mA, which is often rounded to 5W.
However, I am uncertain whether Apple introduced 2.4A power adapter with the iPad.

 

[LeMo]

Slow charging and proud of it

 

[aevan]

Your statement suggests that you believe that fast charging “damages the unit” - that is incorrect but you are entitled to your opinion, and of course to “slow” charging

"Damaging" is maybe too strong a word, but fast charging dissipates more heat, that does shorten the lifespan of a battery. This is why iPhones fast charge to 80% only (when the battery is more vulnerable), then slow down. It's probably not dramatic, and the convenience here makes the small tradeoff worth it. So, fast charging is quite ok, especially in a pinch. Over night? Eh, might as well slow charge, if you can.

But this is not an opinion, it's just how batteries work.

 

[addamas]

I doubt it works on my 11Pro @ 18.1

Either when charging via MagSafe with amazing 2.5-5W in Office (with help of MagSafe case) or when overnight with Apple 5W charger + IKEA MFI braided cable - never had this info.

Only appeared when connected to MacBook and had it almost fully charged then it showed on graph.

 

[Wahlstrm]

If anyone needs help with Apples colour coding:

Green: Keep up the good work!
We’re super excited about seeing you soon again for a battery replacement or an upgrade.

Yellow: *side eye* You’re one of those who take 24-36 months between upgrades, aren’t you?

Red: Dude! Do you even care about shareholder value?!

 

[MasterHowl]

I wish Apple sold their dual-USBC wall charger in a > 35 W version. I travel with mine and struggle charging my MacBook Air and iPhone at the same time.

 

[tomscott1988]

I tend to use slow chargers over night to try and keep my phones battery last longer.

After 4 years my 11 pro was on 91%, I bought a newer faster wireless charger for my iPhone 15pro and after one year its health is down to 91%.

With the my series 8 Apple Watch and only fast charging it and almost twice a day because the battery is so poor it is down to 86% after 18 months.

Fast charging is all well and good but it reduces the battery life span.

TBH im getting pretty frustrated with how much these devices are and how quickly the batteries degrade! Especially the watches. A Garmin with always on display will last 6 days, turn it off it lasts 17. If the battery lasts longer it doesn't need charging as much therefore doesnt degrade as quickly.

 

[kamyk35]

In iOS 18, Apple has introduced a clever new way to identify if your iPhone charging setup is running at less than optimal speeds. The new feature appears directly in Settings, making it easy to spot when you're not getting the fastest possible charge.

The Battery section displays a Slow Charger message when your iPhone detects a "slow" charger in use. You'll also see charging periods with an orange bar. This visual indicator appears in both the 24-hour and 10-day battery usage views.

What Makes a Charger "Slow"?

• Wired chargers providing 7.5W or less power
  
• Standard Qi1 wireless chargers (less than 10W)
  
• USB ports in cars or hubs
  
• Chargers with multiple connected devices sharing power

Common Causes of Slow Charging

Several situations can slow down your iPhone's charging speed. A counterfeit charger could be the culprit, for example. Even some authentic third-party wireless chargers claim MagSafe compatibility but only deliver standard Qi charging speeds.

If you keep accessories like headphones connected during wireless charging, your device automatically limits power to 7.5W to meet safety standards. Running demanding apps, playing graphics-intensive games, or streaming video at high brightness while charging can also reduce charging speeds as your iPhone manages power and heat. Lastly, it's worth bearing in mind that charging in a warm environment may cause your iPhone to temporarily pause charging until the temperature falls.

Get Faster Charging Speeds

To get the fastest possible charging speeds, you'll want to use a USB-C Power Delivery charger along with the appropriate cable - USB-C for iPhone 15 and later, or USB-C to Lightning for earlier models. Alternatively, you can opt for either Apple's MagSafe Charger or any Qi2-certified wireless charger, both of which provide significantly faster charging than standard Qi chargers.

Article Link: How to Tell If You're Using a Slow iPhone Charger

So we have finally learnt what the real purpose of the camera button....Visual Intelligence....I'm a bit miffed it's only available via the camera button, otherwise I'm pleased with where Apple Intelligence is heading

 

[kamyk35]

This article and feature is surprising to me. There used to be a belief that slow (or "trickle") charging is better for the battery. Isn't that still the case? Why is Apple shaming slow charging if it's actually better?

If it's too slow, it can over heat the battery's as well, it's really about efficient charging, any extreme is bad for the battery.

 

[kamyk35]

If you want to get into nitty gritty..

Faster charging does create more heat and that is a fact. (Not saying it will cause damage -- if the term "damage" means degrading the device below it's advertised performance)

Engineers likely designed the device to reach an "acceptable" level of temperature that the battery can tolerate during fast charging. The term "tolerate" is important here.

Because batteries contain chemistries sensitive to heat, it will always impact the performance. That opens up a possibility that by not exposing the battery to fast charging it can extend the life of the battery beyond it's advertised life.

Slow charging also heats the battery and for a much longer period....Apple 15 to 25 watt charging, can in no way be considered fast charging.
What Apple is really saying is either extreme (too fast or too slow) is bad for your battery health and they're right!

 

[kamyk35]

Sure, more current will create more heat, but, battery tech and composition have evolved too.
What it really boils down to is how “fast” is too fast…
But a generic statement that “fast charging” is bad is not true anymore

Also Apple's 15w to 25 watt charging speeds, can hardly be called fast, what Apple is really saying is neither too slow or too fast is efficient and good for the battery

 

[kamyk35]

I tend to use slow chargers over night to try and keep my phones battery last longer.

After 4 years my 11 pro was on 91%, I bought a newer faster wireless charger for my iPhone 15pro and after one year its health is down to 91%.

With the my series 8 Apple Watch and only fast charging it and almost twice a day because the battery is so poor it is down to 86% after 18 months.

Fast charging is all well and good but it reduces the battery life span.

TBH im getting pretty frustrated with how much these devices are and how quickly the batteries degrade! Especially the watches. A Garmin with always on display will last 6 days, turn it off it lasts 17. If the battery lasts longer it doesn't need charging as much therefore doesnt degrade as quickly.

I totally agree with you regarding the Apple Watch battery, It's so poor I'm having to use it in low power mode most of the time, missing out on a lot of it's functionality.
However I've found it's how you use your phone or devise and when you charge it, that makes the real difference.
I've had my 15 Pro for a year and it's still on 100%, however it's set to a max charge of 80% and I never let it go below 40%
My watch series 9 is also still at 100% health, however I mostly use it on low power mode and never let it go below 60%.
Over all I agree that Apple are taking the pee, when it comes to batteries on all their devises, except MacBooks

 

[kamyk35]

I always use apples 5w charger and never see the slow charge message.

People who aren't a techie shouldn't be forced to use a faster charger just to get rid of this message thinking its not charging probably

That's because the message is for when you're charging inefficiently (like in a car) rather than at 5w....ultimately either extreme (too slow or too fast) or with a dodgy cable or charger, is bad for your battery

 

[WarmWinterHat]

I still use a Apple 5w block from who knows how long ago. I only charge overnight while asleep so never cared about charging speed. 🤷🏻‍♂️