Apple's 80% Charging Limit for iPhone: How Much Did It Help After a Year?

[uacd]

So basically, you're going out of your way to put stress on your battery by letting it discharge almost fully and then charging to full. Great advice on what not to do!

I did it to all my devices and smartphones all my life, never had battery issues if only Apple hadn’t packed them for me at the factory (got faulty 6s that never held charge longer than 5 hours and then started to turn off when weather was cool, back then Apple never said what is going on. Turned out that was their secret throttling tech).

If battery is well-manufactured, it ain’t a stress to drain the cells, it keeps it calibrated and in good condition. It is like saying “you should fill SSD only half the size because it won’t be fast”. Well, with newer ones it seems not to be issue anymore and my SSDs only failed due to manufacturing issues (especially Samsung ones, worst ever).

Over the years I learned: if battery doesn’t hold as much as manufacturer promises, return the phone immediately.

Recent nonsense studies show you need to limit charging. Like, for what? Cycles economy? I doubt it works that way. What matters more is how much heat is generated during charging. And you can effectively limit heat by applying less power, i.e. slower chargers.

What is much worse for battery is to never use it at all. Over time it may bloat or lose charge at all

 

[haemolysis]

Absolutely rather run my battery into the ground and then just get a new one.

If the whole point of saving the longevity is so I don't have battery issues, I'm not sure how living with permanent self-imposed battery issues is a solution and not just.... bringing the problem forward.

iPhones don't exactly have all day battery life. Never a day goes by that I don't have to use the charger. And I'm supposed to use it with a chunk missing?

 

[rabuha]

iPhone 15 Pro Max since September 2023
80% limit
Mostly Magsafe charging during night
100% capacity, 195 cycles

 

[z4co]

You're straight up wrong, no doubt about it.

There's plenty of science that you're not aware of. Not sure why you would reference a blog instead of peer reviewed journal articles.

https://www.sciencedirect.com/science/article/abs/pii/S2352152X19314227

View attachment 2427491

Nice reference here.

To explain why the loss is greater for charging at 100% than running to 0%, the graphite anodes can get damaged if excessive Li is inserted over its capacity. Essentially, once fully charged, additional lithium ions can no longer find free sites in the graphite layers and they start to form metallic Li clumps and eventually dendrites that “exfoliate” the graphite layers, permanently reducing the maximum charge capacity.

Edit: other factors too like electrolyte decomposition can occur too.

 

[d5aqoëp]

LMAO. I have my 15 Pro Max still at 97% health 220 cycles with 100% battery charge default setting. This 80% is bogus and a good way to torture yourself.

Battery manufacturer: Desay

 

[Agilis]

iPhone 15 Pro Max: Maximum capacity: 90%, Cycle Count: 300, First Use: September 2023

This was with heavy use, charging to 100% via MagSafe overnight & USB C when possible. This was with Optimized Charging enabled.

 

[svish]

Have not enabled it. Don't think it will have a huge impact on battery life.

 

[amaze1499]

Lithium-ion batteries experience more stress when charged to full capacity (100%). Most of the degradation happens in the top 20% of charge. By limiting the charge to 80%, you avoid the constant-voltage phase, where the battery endures more wear due to higher voltage and thermal stress.

Adjusting that setting can nearly double the battery's cycle life, allowing more charge-discharge cycles before significant capacity loss occurs according to University of Michigan battery research group.

 

[Supermallet]

Some of this feels like a lottery but I’m at 97% after 281 cycles with a launch day 15PM. I set my charge limit to 100%, turn on optimized battery charging and clean energy charging. I charge overnight with a 5W charger and usually end the day anywhere between 30-50% depending on how much I’m using it. Days with very heavy usage I will do a fast charge top off to 80% in the afternoon but usually I don’t need to.

The only time I use wireless charging is in my car and I work from home so I don’t use it that often.

 

[MasterControlProgram]

98% and 162 cycles. I’ve had the phone since launch and have the 80% limit enabled. It seems I charge my phone a lot less than most judging from the cycle count!

 

[arobert3434]

iPhone 13 mini after one year was 100 cycles and 100% health according to Coconut Battery. (Started at 103.4% when new mind you.) After two years and 300 cycles (usage changed to include a background app that doubled battery consumption), 90%. Coming up to three years and 480 cycles, 88%. I guess the 80% mode would have helped me to the tune of 5% extra, but 0.95 * 0.8 = 70% vs 90% so the benefit is not apparent, except to boost resale value.

On the other hand my Macbook Pro after three years and 290 cycles was at 84%. Tougher life, apparently.

 

[0014]

15 Pro Max from launch day. Mostly MagSafe charging (probably 85% of the time). Have an automation that switches on LPM at 25%.

When my 16 Pro Max comes I am going to charge it exclusively with a 5w USB-C charger and see how that fairs. I think wireless charging and higher charge rates negatively impacts the battery.

 

[empersance]

Just... use your phone

You might save around 3-4% of battery over the phone's entire lifespan if you're lucky (battery manufacturing). But in exchange, you're willingly shortening its overall battery life by around 20%.

If you're not using the phone much, that’s fine. But if you're at risk of running out of charge during the day, why would you want to do that? It just doesn't seem worth it.

 

[metkis]

This feature primarily applies to environmentally friendly users that refuse to get a battery replacement at the 80% mark and desire to keep their phone at peak performance for 5 years.

Here’s why:

The average iPhone with optimized charging is likely to degrade upwards of ~7.5% per year. Let’s graciously say you halve that degradation amount with the 80% limit, or ~3.75%;

Note: This is contrary to my experience of 4.5%/yr with optimized charging on a 13PM and the writer’s experience of 6%/yr with the 80% limit on a 15PM, but I digress.

Using our optimistic percentages, after 5 years the regular user will see degradation of 37.5%, alongside the an estimated 62.5% battery health (Ouch!). The limited user will have a degradation of 18.75% and a battery health of 81.25%, but a simulated (-20%) battery capacity of 61.25%. In other words, both would be experiencing similar battery performance at this point.

The limited battery would technically be within spec, but will soon hit the 80% battery life mark where Apple recommends replacement. The non-limited phone would technically be there sooner in 3 years, but would have enjoyed superior battery life that entire time.

For the capped user, turning off the feature at the 5 year mark would finally give the most gratifying benefit of the feature — a battery that would feel the same as the phone when originally capped. After that, the point begins to be lost.

My advice? Instead of limiting the charge percentage, limit your personal phone usage by 20% and delete or disable apps using lots of background activity. It’s far more likely to meaningfully increase the longevity of your battery and you’ll have that extra capacity when you need it.

 

[grebenarr]

15 Pro Max, 100% capacity here (in fact 101%), 241 cycle, 1yrs old exactly. I've never let it go up over 80%, but not below 20% either. I think it is key also.

 

[empersance]

By the way i have an iPhone 13 with 458 cycles at 86%

And even if I want to, I can't limit to 80% because of Apple

 

[kirkmc]

I did it to all my devices and smartphones all my life, never had battery issues if only Apple hadn’t packed them for me at the factory (got faulty 6s that never held charge longer than 5 hours and then started to turn off when weather was cool, back then Apple never said what is going on. Turned out that was their secret throttling tech).

If battery is well-manufactured, it ain’t a stress to drain the cells, it keeps it calibrated and in good condition. It is like saying “you should fill SSD only half the size because it won’t be fast”. Well, with newer ones it seems not to be issue anymore and my SSDs only failed due to manufacturing issues (especially Samsung ones, worst ever).

Over the years I learned: if battery doesn’t hold as much as manufacturer promises, return the phone immediately.

Recent nonsense studies show you need to limit charging. Like, for what? Cycles economy? I doubt it works that way. What matters more is how much heat is generated during charging. And you can effectively limit heat by applying less power, i.e. slower chargers.

What is much worse for battery is to never use it at all. Over time it may bloat or lose charge at all

You don't need to calibrate lithium-ion batteries. You're repeating what was necessary with nickel cadmium batteries, which is no longer the case. Apple clearly explain this on their website when discussing how to care for batteries.

 

[Ifti]

Get a new phone and baby it so much, all so that the next person can enjoy it more then you did.
Seriously, enjoy your purchase. Why worry about the odd few % in battery health. I do generally remove my handset from charging (wired) at around 90% most of the time, but I do not set it to stop at any level. If I get to it when it's between 80-100% I'll remove it from charging. If I don't then so be it! Doesnt really bother me.
My handset will be handed down to a family member once I'm done with it, and if the battery is that bad I'll just have it replaced.

 

[Wedlock]

I have my iPhone 15 Plus for 8 months now and i always charge through USB-C up to 100 % full battery.
My battery is at 100 % with 103 cycles of charging.

So i charge the iPhone after two days of usage and granted even though i make calls and use various apps on the phone during the day i like to see myself as an average using person. Still when i sold my iPhone 14 plus it was at 98 % with over 250 cycles with one year of owning and using it.

 

[kirkmc]

Nice reference here.

To explain why the loss is greater for charging at 100% than running to 0%, the graphite anodes can get damaged if excessive Li is inserted over its capacity. Essentially, once fully charged, additional lithium ions can no longer find free sites in the graphite layers and they start to form metallic Li clumps and eventually dendrites that “exfoliate” the graphite layers, permanently reducing the maximum charge capacity.

Edit: other factors too like electrolyte decomposition can occur too.

But the whole point of battery management software is to prevent them from going over capacity.

Interestingly, my electric car, a Peugeot e208, has a 50 KW battery, with 45 KW usable. I assume that means that as the battery degrades, the software controlling the charge will allow it to use the originally unusable cells to keep capacity around the nominal level.

 

[dz5b609]

99% battery life after a year with 240 cycles, had it at 80% limit for 95+% of that time.

 

[w_aldo]

The idea of charging between 20 and 80% was born because of a coincidence (read more here) and it is not based on anything truly scientific. The best thing a user can do is to let macOS/iOS/iPadOS manage the battery as it wants.
Actually, always keep your device as charged as you need, that is, use it normally. When it falls below 45-50%, charge it up to 100%! The only thing you should try to avoid—though nothing dramatic is going to happen if you forget this a few times—is to keep it plugged at 100% for too much time.
My 2023 MBP has 226 cycles and 98% health (though Coconut Battery says about 95%). I've charged it to 100% always and charged anytime between 10 and 50% when needed. I believe we users have many more important things to worry about than battery health.

You’re completely wrong, and the 20-80% rule is a scientific fact and not a coincidence at all. What are you even talking about? Please see here and here.

Just because you don’t think it’s important, doesn’t mean it’s not a real thing. You’re just saying that because it’s convenient for you to have that belief.

 

[l0ken]

iPhone 15 Pro
Using 80% limit since day 1
First use: September 2023
97% capacity
174 cycles

I rarely use it at home, though. And i don't know if i f....d up by interrupting it charging to 100% sometimes even though a limit was set. I didn't know it was intentional and was never given any reason.

 

[kirkmc]

How does it feel to just lie on the internet? You’re completely wrong, and the 20-80% rule is a scientific fact and not a coincidence at all. What are you even talking about? Please see here and here.

Just because you don’t think it’s important, doesn’t mean it’s not a real thing. You’re just saying that because it’s convenient for you to have that belief.

The blog he cites is from someone who knows what he's talking about, but I don't see anything in the article about a "coincidence." The article points out that Macs - and by extension iPhones - have software to manage the charging and that people shouldn't worry about it. Above 80%, batteries trickle charge.

I'm surprised that, in the past few years, Apple has started including settings to stop charging at certain percentages. Using their optimized charging is probably best, and obsessing about 80% (or another percentage, because since the iPhone 15, you can choose 80, 85, 90, or 95%) seems counter-productive. interestingly, watchOS 10 offered an 80% limit, but now only offers optimized charging.

 

[kirkmc]

One interesting bit of anecdata: I don't recall whether this was my iPhone 12 Pro or 13 Pro, but one of them showed 106% battery capacity when I first bought it, and for nearly a year. Then it dropped precipitously.