iPhone 16 Pro Max 80% Charge Limit: One Year Later, Was It Worth It?

[Ronald Reagan]

You should run this test without using wireless charging. I think this is a much more important part of the equation. My wife tried using it once in a vehicle and the phone got crazy hot. Heat is a killer. I never use it. Right now, I have 430 cycles on a 15 Pro Max at 95% (was at 98%, then after a major update it mysteriously dropped to 95%). My wife’s 14 Pro Max is sitting at 98% (of course, cycles are unknown). Mostly use the 5w apple charger. Suits me fine 90% of the time.

 

[840quadra]

1 or two years really isn't a significant test period to produce enough sample data, especially when we are talking less than 300 "cycles" which itself is a nebulous term. Apple defines a cycle as "This is the number of times iPhone has used your bettery's capacity". Well my 16 pro says I have 231 cycles, I am 100% sure I have not run it down to zero (auto power off) that may times in 1 year. While doing that repeatedly would be bad for the battery long term, it is an important data point for the phone to calculate the true battery health.

People claiming they wirelessly charge their devices to 100% all the time and state their phones are in the high 90 - 100% health are likely not wrong, as the phone's BMS (Battery management system) is only estimating true health based on formulas that Apple is using within iOS, which is simply an estimate only.

Any phone that hasn't gone through a full calibration cycle, by starting at 100%, fully discharged (to zero), followed by a full recharge and hold, likely will have only a "best guess" battery health estimates to begin with, as the device hasn't had a good opportunity to calibrate.

Sorry but it is a fact that heat, fast charging, prolonged full charge state, and prolonged depleted battery state negatively impact this type of technology. This is why EV batteries in automobiles have cooling systems, and most any owners manual for such cars will clearly outline that fast charging when done frequently will impact the longevity of the pack. similarly, a growing number of Lithium Ion equipped devices have auto-discharge functionality to help save battery logevity. For instance, DJI drones will auto discharge their battery packs to save their long term life, Datacenter UPS system batteries will auto discharge / slow recharge cells to maintain battery life, without impacting (much) the total available UPS battery time in the event the system is needed. The BMS systems in these are advanced enough that many manufacturers (Samsung, Toshiba, ETC) offer 10+ year warranties on their lithium technologies.

TLDR, if you are only keeping a phone for 1 or two years, 100% charging, wireless charging (which produces more heat), and fast charging will not likely impact your daily use. However, it will (quite likely) impact the long term longevity of the device battery for the 2nd, or 3rd owner unless the cells are replaced.

 

[Karen44]

With the iPhone 15 series, I did an experiment and kept my iPhone's Charge Limit set at 80 percent for an entire year. It provided an interesting look at the impact of charge limits on battery longevity, so I decided to repeat it for the iPhone 16 line.

Since September 2024, my iPhone 16 Pro Max has been limited to an 80 percent charge, with no cheating. As of today, my battery's maximum capacity is at 94 percent with 299 charge cycles.

With last year's test, I spent a lot of time with my battery below 20 percent. I saw some comments suggesting that draining it so low could also affect battery capacity over time, so this year, I tried hard to keep my battery between 20 and 80 percent. I wasn't always successful, but my iPhone 16 Pro Max was in that middle charge area most of the time.

You can compare your own battery health with mine, but my guess is that my 94 percent battery capacity is about average, regardless of whether charging limits are on or off. In fact, my iPhone 15 Pro Max was also at 94 percent capacity at the 12 month mark when I did this same test last year.

I did a mix of charging via MagSafe and charging with USB-C, and my iPhone 16 Pro Max can get hot when charging over MagSafe, especially with MagSafe battery packs. Since I was trying to keep above a 20 percent charge, I did more wireless charging when I was out. I can't help but wonder if heat was an issue this year.

It continued to be inconvenient limiting my iPhone battery to an 80 percent charge. It was fine when home, but if I was out and wanted to use the camera or needed GPS, it often wasn't enough battery. When you set an 80 percent charge limit, the iPhone will charge to full every so often to calibrate, and I appreciated surprise days with 20 percent extra battery.

If I had to guess, I probably had a 50/50 split between MagSafe charging and fast charging with USB-C. Most charging was indoors at around 72 degrees, but there were times when I was outdoors with a battery pack in warmer conditions.

I use my older iPhones for software tests, so my iPhone 15 Pro Max is still around. At the two year mark, its capacity is 88 percent, down from 94 percent in September 2024. It has 352 cycles, and I've kept it at the 80 percent limit.

During this year's testing, my iPhone 16 Pro Max battery was still at around 98 percent just a couple of months ago, so I thought the limit was having more of an impact, but I saw a decent drop as we got closer to September. It was even at 95 percent about a week ago, but now I'm down to 94 percent.

I now have two years of data with my iPhone limited to an 80 percent charge, and I don't think it's been worth it. My coworker who also has a 16 Pro Max did not have an 80 percent charge limit set, and his battery capacity is 96 percent with 308 charge cycles.

Maybe setting an 80 percent limit improves battery health over a longer period of time, but over a one-year period, the results have been disappointing. Setting charging to a 90 or 95 percent might make more sense.

I have upgraded to the iPhone 17 Pro Max and did already limit it to an 80 percent charge for another 12-month test. I'm interested to see how the larger battery changes things, and whether the switch to aluminum will make a difference.

What's your iPhone battery capacity and cycle count? Let me know in the comments below, and weigh in on whether you think the 80 percent charge limit is a good idea.

Article Link: iPhone 16 Pro Max 80% Charge Limit: One Year Later, Was It Worth It?

Just checked my 16pro battery life. It is at 100%. I have my charging set to 85% and I have been charging with the cord as the mag safe was making the phone quite warm.

 

[Larrie]

I have a second generation iPhone SE purchased shortly after they came out in April 2020. It is charged to 100% every night. The maximum battery capacity is currently 77% with approximately 1800 charge cycles. I use it about 6 hours a day.

 

[Hobbes44]

I’m on a 16 Pro Max. 11 months old and 243 charge cycles, and 99% health.

I charge via cable or magsafe but mostly on 5w or 10w chargers

 

[wakeboardandy]

16 Pro. 444 cycles and 95% battery health. Always charged to 100%. I exclusively charge via magsafe. Since I changed to magsafe only charging a couple of years ago my battery health is much better. Maybe it’s the slower charging rate of magsafe that is better for the battery.

 

[wakeboardandy]

The only thing that makes a difference is wireless charging or not. Phones using wireless charging suffers significantly worste battery after two years.

I’ve found the complete opposite. MagSafe charging exclusively has been much better for my battery health over the last few iPhones.

 

[ColoradoBillsFan]

Mine is at 92%....

 

[LKN_G_Man]

iPhone 16 Pro Max, 80% charge limit, 228 cycles, 100% capacity remaining:
Much of the time I'm not too far from a charger, but I do have a period of 4 to 5 hours each day where that is not the case. If I see the charge drop into the 20s and I don't anticipate being back to a charger soon, I don't hesitate to hang on a MagSafe power bank. I'll leave that connected until back to a charger. Sometimes it may get me back to 80% first. Then I'll go back to battery. My phone gets a wired charge with CarPlay and overnight, MagSafe all other times. After reading most of the comments, I'm not sure if it makes a difference, at least with iPhones bought during the last couple of model years. Apple obviously has some really good power and battery management capabilities under the hood now. Kudos! Although I've been getting a new iPhone every year, I'll continue with charge limiting. Who knows, I've always believed in taking care of what I have in case I may not be fortunate enough to replace it. The jury's still out on the long term benefit of charge limiting.

 

[joeblow7777]

Battery health might be the dumbest metric Apple has ever introduced. Mine changes when I update OS’s and other random things. It literally feels like there is no science behind this algorithm. I’m not sure why people even care?

That's why they never used the show it until people realized that their performance was slowing due to the battery health declining, and accused Apple of planned obsolescence. They then had to make battery health transparent. Most people don't realize that it's always just an estimate, which is why it seems to change randomly at times. Now people obsess and worry about every percent.

 

[The Doctor11]

So you’ve limited yourself to conserve the battery but then used the most damaging charging method overnight when the method of charging doesn’t impact you in anyway? You’re asleep and not using your phone, so may as well use a slow cabled charger. That there is an example of a pointless exercise.

I literally don’t need more than 85% in a day, so it doesn’t matter, might as well give it a try.

And I highly value the magnet charger before bed. I just toss it on the night stand and it works. No fumbling, no looking for the cable.

I also get calls in the middle of the night, it’s seamless and automatic to get it off the charger to answer the phone.

We all have different needs and values.

 

[bviktor]

It's heat that kills your battery, not charging to full.

Just buy a phone stand with a fan on the back plate from Aliexpress for $10, charge via wire, and you're good.

Avoid wireless charging like the plague, all it does is add more heat. The ultimate battery killer.

Been using my 16 Pro like that, 155 cycles, 8 months, 95% limit. Battery health still at 100% <knocks on wood>

 

[mlody]

I have 16 Pro, 201 cycles, 100% max capacity, First use Sep 2024, Manufacture Date July 2024.
Wife has 15 Pro 863 cycles, 86% max capacity, First use Oct 2023, Manufacture date Sep 2023.

We have a mix of charging, some days we do 100%, others we do 85%.

 

[HazeAndHahmahneez]

I have done experiments with the 80% limit on iPhones and MacBooks for years.
With my iPhone 12 Pro Max I didn't have the iOS option yet but created an automation to warn me when at 75% such that I could stop charging, which I almost always did. My wife had an iPhone 12 Pro that charged to 100% daily. Results after two years: my battery condition was significantly worse than hers.
With our iPhone 14 Pro's we started out the same. After 6 months, hers was still at 100% while mine had dropped a couple of percentages. I stopped at that point.
On my MacBook Pro's (multiple generations) I had an application called AlDente that can limit charging at whatever percentage you choose. Here I also had a comparison for the last two MacBook Pro's I had as my son had equivalent hardware that we could compare. With the MacBook Pro's the results weren't as convincing as with the iPhones, but still my MacBook Pro's didn't fare better in battery quality than his.

End result: I don't buy it anymore that limiting to 80% helps keep your battery in better shape.

Great vigilance. Love ppl like you who experiment with intent and control to get answers and results. Awesome stuff…

I agree with you, it’s not worth it like many said EXCEPT for those like @erthquake who claim to limit it at 80% and constantly keep it plugged in (like Lyft drivers or something). I think the limit is basically just for those types of ppl. Regular use, charge when you want (overnight, top off during the day etc) we should just keep it at 100% for most battery life (in case of emergency…anything less than 70% is Sketchville, for real).

My question is how does adaptive power mode work? Does it shut off automatically if you’re plugged in and charging?…don’t want to limit anything if it’s plugging and not in danger of completely draining…

 

[satpak]

Maybe setting an 80 percent limit improves battery health over a longer period of time, but over a one-year period, the results have been disappointing. Setting charging to a 90 or 95 percent might make more sense.

Why would 90 or 95% make sense?

 

[LightProtector]

Same phone charging to 100%:

View attachment 2558392

Hmmmm

I’ve just turned off the optimised charging on my watch lol

I keep my phone plugged in a lot, and I also live in Florida so my phone also gets hot a lot. Doesn’t help that my case isn’t good at dissipating heat. Also, I think there’s a lottery with batteries as well.

 

[LightProtector]

My 15 Pro Max, now almost two years with more or less the same number of cycles (440 to be exact) is at 84% health now for a long time with no restrictions on charging. Always set to charge to 100%. Not sure whether the feature is very useful.

Where do you live? Do you live in a warmer climate?

 

[LightProtector]

I have my 15PM set to 95% and I have 680 cycles and it's at 86% so it doesn't seem you're seeing any benefit. the battery life sucks for a long time now on mine.

Damn that’s good. It also might be due to climate. I live in Florida and it’s hot here.

 

[ignatius345]

This. Though out of curiosity, do you ever do anything that gets it pretty hot? Or have much heat exposure in general? Yours definitely appears to be holding up better than average.

I often charge it on a really slow old qi 1 charger overnight. But also charge it on faster ones throughout the day. ¯\_(ツ)_/¯

 

[AeroSatan]

Charged the 16 PM to 100% before going to bed, it wasn’t being charged overnight. Woke up to 100%, trading it in right now for the 17PM with about 220 cycles and 99% battery health.

 

[Toratek]

I (somewhat regretfully) shipped off my 16 Pro on the IUP program earlier today, tried the 80% thing for a couple of weeks overall, but quickly found that led to low battery too soon in the day. So, I generally ran it to 100% (adaptive for a week under iOS 26) charge.

Battery health was still reported at 100% when I erased and boxed it in the IUP return box this morning, with something like 340 cycles.

Generally, phone sat nightly on a MagSafe charger and wired in my car. Rarely did the phone get under 30% battery the entire time. Lots of travel, seven trips to Japan and two to Europe, so often recharged from an Anker battery pack or my old Apple MagSafe lightning battery pack. Generally would recharge at around 35-40%.

First phone I ever had that maintained 100% after a year, the 15 Pro was shipped out at 94% with the same general charging regimen.

I think the phone was left in a hot car twice in the past year. Other than that, it only ran hot when doing an iOS update or heavy video recording.

I hope it wasn't some sort of unicorn!

 

[adampk17]

iPhone 16 Pro Max bought about 2 weeks after launch. I've been at the 80% charge limit 99% of the time and I'm at 100% battery health with 238 cycles.

The difference might be that I try not to use wireless charging at all.

 

[Dog Bone Malone]

I always charge to 100%. My battery is just fine.

 

[pinkkie]

iPhone 15 Pro on iOS 17.7, 103 cycles after a year, health 100%. The sw charge limit is a snake oil that only makes your battery degrade faster because you don't use its full capacity.

 

[N47H]

I literally don’t need more than 85% in a day, so it doesn’t matter, might as well give it a try.

And I highly value the magnet charger before bed. I just toss it on the night stand and it works. No fumbling, no looking for the cable.

I also get calls in the middle of the night, it’s seamless and automatic to get it off the charger to answer the phone.

We all have different needs and values.

What are you giving it a try for though if you don’t need more than 85%? What’s the need for trying to keep max capacity at 98% rather than say 96% if you don’t ever use that extra capacity? Plus if you’re setting your battery charge limit to 85% for battery health purposes then what you need to be looking at is do I need more than a 65% charge? Because going below 20% is as bad as going up to 100%. Letting is shut off and drain entirely is even worse for the battery.

A cable clip holding the cable onto your bedside table or whatever would cost less and do more for your battery health than saying it’s too hard fumbling for a cable so may as well damage it with a wireless charger. And you don’t need to unplug it from the cable to answer these phone calls you get in the middle of the night (I assume you’re an on call doctor given the username!).

Anyway, not here to tell you what to do, not here to argue with you, merely advising and explaining where these battery health measures make sense and how they work. It’s far more than switching a setting on, you need to change charging habits and be aware of usage limitations otherwise it’s doing nothing. Enjoy your phone anyway, nice discoursing with you.