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Apple's 80% charging limit for iPhone: How much did it help after a year? (macrumors.com)
45 points by Tomte 68 days ago | hide | past | favorite | 63 comments



I made may own 70% limiter for Android. After 5 years the battery was like new. AccuBattery also said it was at 95% capacity.

But scheiße, I had to buy new phone anyway, because banking app refused to work on Android 6.


I bet the collection of potions you've managed to accumulate after you've beaten the final boss must be really impressive!


ChatGPT: "Yes, the sentence contains humor. The basic idea is a playful comment about how, after finishing a game (especially after defeating the final boss), players often end up with a lot of items or potions that they might not have used or needed during the game. Such a collection is somewhat pointless after victory since all the challenges have already been overcome.

The humor comes from pointing out the irony of having this "impressive" collection, which is no longer useful: the player has already completed everything important, but still managed to gather many potions they might not need anymore."


Here is a proper explanation in order to exorcise this unholy comment.

https://tvtropes.org/pmwiki/pmwiki.php/Main/TooAwesomeToUse


It's not fitting (at least in my case).

I use 80% limiter. 80% gets me through my normal weekdays, I usually end up with ~40% in the evening. Charging the battery to 100% daily has exactly 0 benefit, except wearing down the battery.

I disable the 80% limiter on the weekends, where I'm more likely to need the extra 20% (plus the capacity not lost through the excessive wear).


Not to be rude but your (any) situation isn't relevant. The joke is that this is all rather performative when the lifetime of the device isn't as long as it could be

Burn that battery. That's what it's there for, the OS or carrier whims like baseband will probably expire first. If it survives for use off the charger, you've won.

There, we've now gone the gamut. A person made a joke, someone repeated it, first person used an LLM to explain it, another person provided the actual source... and now I'm here ruining it further!

I'll buy a new/cheaper/dumber phone before I lean further into this ecosystem or feel anxiety over it. They want disposable, it'll be disposable.


> The joke is that this is all rather performative when the lifetime of the device isn't as long as it could be

I don't replace my phone every 6/12 months and I don't really want to replace the battery so frequently either, mainly because of the hassle.

I've noticed that some people get really insecure/defensive about this question, and have this urge to prove that optimizing your battery usage can't be worth it.

But isn't it plain obvious that it's a trade-off which can come out differently based on your subjective priorities?


>and now I'm here ruining it further!

Come on, let's finish it all the way.

https://tvtropes.org/pmwiki/pmwiki.php/Main/DontExplainTheJo...


Is your app in the Play Store?


No apps here. It is just a Wifi-plug and Termux. It reads the battery voltage with termux-battery-status and turns the plug onoff. It does various other things too and there are issues, which I dont remember, so here is the entire program.

  import os,json,time
  loki="../batcon.log"
  f=open(loki,'w')
  f.write('ALKU\n')
  f.close()
  lokinolla=time.time()
  alku=True
  while True:
    b=json.loads(os.popen("termux-wifi-connectioninfo").read())
    if b['ip'] == "192.168.1.205":
        os.system("termux-api-start")
        os.system("termux-wake-lock")
        a=json.loads(os.popen("termux-battery-status").read())
        if alku:
            alku=False
            os.system('termux-notification -c "BATCON TOIMII"')
        p=a['percentage']
        s=a['status']
        cur=a['current']
        if p<70 and s=="DISCHARGING":
            yes=int((time.time()-lokinolla)/60)
            if yes>0:
                fi=open(loki,'a')
                fi.write(str(yes)+" "+str(cur/1000)+"\n")
                fi.close()
            os.system('curl 192.168.1.156/ON')
            lokinolla=time.time()
        if s=="CHARGING":
            if p>70: os.system('curl 192.168.1.156/OFF')
            if p==81:
                os.system("termux-tts-speak -l fi LASTAUS EI LOPU &")
                if 0!=os.system("ping -c 1 192.168.1.156"):
                    os.system("termux-tts-speak -l fi LATURI EI VERKOSSA &")
                time.sleep(30)
        if 0==os.system("ping -c 1 192.168.1.118"):
            os.system("termux-volume music 15 &")
            os.system("termux-tts-speak -l en YOUR FRONT DOOR IS OPEN! &")
            time.sleep(30)
        if 0==os.system("ping -c 1 192.168.1.219"):
            os.system("termux-volume music 15 &")
            os.system("termux-tts-speak -l fi HUOMIO... JÄÄKAAPIN OVI ON AUKI ! &")
            os.system("termux-toast -b yellow -c black  JÄÄKAAPPI")
            time.sleep(30)
    else:
        alku=True
        print('No KOTIKONE')
    time.sleep(30)


Does your fridge only get an IP when the door is open?


Yes. It is battery-operated esp-01, which gets power when door is open, establishes wifi-connection and after few minutes goes to machine.deepsleep().


I’ve always viewed this feature as similar to the plastic covering you sometimes see on old people’s couches. Sure, it makes the thing last longer, but at the expense of being notably worse the entire time you own/use the thing. I’m not crippling my device just to marginally increase its resale value some point down the line.

If the concern isn’t resale/trade-in value, then it makes even less sense because it’s going to be YEARS before your battery life that you’re intentionally throwing away 20% of is going to be less than someone who uses the full capacity but has a slightly more degraded battery.


I’m at 89% health on a 15 Pro after a year of 80% limited charging – which is less than what my 13 Pro ended up with after a year of optimized charging. I wonder if this is due to regular deeper discharges (I often end the day on 5% or less).

Seems like it’s not worth the hassle at all at least for me.


Just to add a data point: my iPhone 12 Pro Max stands at 82% with optimised charging after 4 years.

Not bad at all.


80% optimised charging, 100% battery life. iPhone 15 Pro, manufactred - September 2023, first use - November 2023.


I suspect it would work for me as I rarely dip below 50%. My current phone doesn't support it though.


89% health with 100% charge limit and “optimize battery charging” enabled.

15 pro max, first used October 2023.


97% battery on 15 Pro Max after one year of use (september 2023).

80% limiter has always been active.


15 pro optimised charging still at 100% health

Edit: since first use Sep 2023


vanilla 15 bought on launch day, 238 cycles, 98% condition.

I also set it to 100% when I know I won't be at my desk for longer than normal (i.e. trips).


I’m at 88% on an iPhone 14 purchased Nov 2022


There's always a variance in batteries, but yeah, deep discharges like that cause a lot of wear.


> It's difficult to see when the 80% will ever pay off.

Two words: resale value

Aside from lack of scratch and dent wear, showing a 98% - 100% battery health is very convincing that the phone is "like new".

This gets you back up to the "refurb" price levels instead of the "trade in" price levels from Apple or Gazelle.


People have never asked me "but what's the battery retention like?!". I put it up for a price, people pay that price.


It was pretty much the only question people asked on Swappa, until they just added it as a required field for the listing.


It's difficult to see when the 80% will ever pay off. They're a year in and he's got 94% health - but with that limit in place that's an effective battery capacity of 73% (0.94*0.8). At the rate that the others' batteries are degrading it's going to be close to 2 years before they even hit 80% capacity let alone the 60-70% that would make the 80% limited battery have better total real battery time. And at that point what are we saying? You're trading a good chunk of your battery in the first two years of its life for a few percent more several years into owning the phone?

It seems difficult from these numbers to see when, if ever, this choice is going to pay off for the people who opt in.


I suspect it was conceived for Apple to prevent having to replace batteries under warranty.


Seems like if that was Apple's goal, it would be easier for them to just reduce the quoted battery life of the phone, limit the charge to 80% for everyone, and relabel the 0-80 scale to 0-100.

Presumably, they've already effectively done this by choosing voltage amounts that balance warranty repairs with battery life. e.g. the iPhone 15 charges to a max of 4.48V, but the battery presumably physically supports some higher voltage for "100%" that would give more capacity and less lifespan. (Notably, different iPhone models have different voltage ranges.)


"reduce the quoted battery life of the phone" - This is the bit that presumably they don't want to do.

Reducing the top-line specs of the phone means that it might fall down in comparisons to others in a spec-comparison.

I presume they would rather move the conversation into customer-land, i.e. once you've bought your phone they talk about how they are acting to preserve your expensive device.


The older feature of limiting charge to 80% only overnight was more useful in my opinion.


Does iOS have charge-rate limiting?

I usually only have regular "fast" charge enabled on Android not super fast charge. (10w vs a ~18W on my Samsung S22).

I'm curious how much effect the charge rate limit has. It's not a huge charge rate difference on my phone, 10 vs 18W; I'd imagine higher rate charge devices might benefit more.


Android keeps the battery at 80% for most of the night, only charging it to 100% 1-2 hours before your alarm time. That way, you start the day with a full battery, but it isn't needlessly kept at 100% for an extra 6 hours or so where you almost certainly won't need it.

It's hard to say what contributed most (the charging strategy, more durable batteries, better battery life in general) but battery life has not been a concern at all, even on days with heavy use. Even if I forget/fail to charge in one night, I'm usually OK.

The article says that the author ran out because they were "without a charger for most of the day" - is it normal that a new-ish iPhone, even if charged "only" to 80%, needs to be charged during the day?!?


> is it normal that a new-ish iPhone, even if charged "only" to 80%, needs to be charged during the day?!?

Depends heavily on usage patterns. I have friends who watch TikTok videos all day, and they have to top-up before they go out for the evening. If you have less battery-intensive habits, a new-ish iPhone goes 2 days on a charge fairly easily.


I assure you that a sizeable portion of Android users also need to charge multiple times a day. Behaviour is everything.


You'd probably need to get a random sample of a few hundred phones of the same type to get a reliable view of how well the charging limit actually works. It's very likely that the battery health indicator people are seeing on their phones is primarily dictated by how good a battery they got when they initially bought their phones.

AFAIK, these batteries have a tolerance range of around ±5%, so if you just have a sample of two phones, one might end up with 100% battery health after a few hundred cycles and the other with battery health in the low 90s due to no factor other than battery lottery.


Even if you use the 80% limit how you use the device is what really matters, for example if you leave the phone a lot exposed to the sun on your car that will kill the battery fast regardless of how you charge it.

Heat is the main culprit.


I enabled the 80% charge limit from day one (September 2023) and after 159 cycles it is still at 100% maximum capacity.

I think it is also crucial to not allow deep discharge of the battery too frequently. Ideally keep the battery charge in the range of 40-80%. My usage is relatively low so I am mostly within that range.

Infrequently I have charged to 100% for longer days away from home. Enabling low power mode helps to prolong battery life on these occasions too.


They don't say whether the control group is using `Optimised Battery Charging` or `None`. (I assume it's the former.)

Would be interesting to compare all of the three options.

It seems that maybe (for MacRumors staff members?) Optimised Battery Charging already provides most of the benefits of 80% Limit, since the devices are fully charged only for short amounts of time anyway.


I came to pretty much the same conclusions.

My iPhone 15 Pro is at 97% battery health after 287 cycles. My "normal" usage with "optimized charging" will usually result in a phone with 95% - 98% health after a years.

I think the major thing here is number of cycles. I normally charge once per day, at night while sleeping, and with optimized charging i almost never need to charge my phone during the day. With 80% limit enforced i found myself needing to charge late afternoon 2-3 times per week, especially towards the end of the 12 month period.

My point is that i use the same amount of power during a day, regardless of charge limit on the phone, so the number of cycles will be somewhat identical, with the only difference being that with optimized charging i start with 100% battery and plug in around 30%, and with 80% limit i plug in with ~10%, and low SoC (<20%) is almost as bad as high SoC (>80%) for Lithium batteries in EVs, and i doubt it's any different in phones.


A cycle is just a full charge/discharge. If you use 50% today, charge to 100%, use 50% again, charge to 100%, then that's one cycle, not two.

A battery is just a bag of chemicals. Starting to charge it doesn't have any kind of startup cost.


I hope it’ll become the default practice for the world’s sake, although I’m not sure the incentives are there - it seems like an EU anti-waste regulation waiting to happen, though.


In my annecdata experience deep discharge (< 5%) and partly charging (like 40 to only 60%) affect the capacity severely. There the annecdata of the OP is not very relevant.


Interesting. I’ve always understood that partly charging was supposed to be better for battery health with lithium batteries.

I’ve capped my 15 Pro Max at 80% from the start and I avoid going below 20% and it’s still at 100% battery health after more than 10 months and 159 cycles. I occasionally charge from ~20% to a random higher number during the day, but other than that I just let it charge during the night. My iPhone 12 Pro Max dropped to 90% battery health in no time without the 80% cap and a similar charging schedule with optimized charging enabled.


I turned off all the charging optimizations on my day 1 14 Pro and I'm still only at 82% battery health and everything 'seems' fine two years in.


4 years into a 12 Pro Max with zero optimization. Been at 84% for a while now.

Locking myself to 80% is silly since I'd much prefer that 20% as a buffer in important situations instead of having an extra 1% in some theoretical point 5 years in the future. I've been at 2-3% remaining while trying to find a hotel in a new city/country and starting the day with a 100% charge has saved my ass countless times.


13 mini here, 2.75 years in, 83% health. Similar stats, but I'd say NOT fine - it feels like it runs down fast and I don't trust it to last all day.


I literally discharged my 12 mini so fast in last couple of months of its two year applecare warranty, just to get a new battery. Got it done. Phone is visibly lasting so much longer now.

iPhone likes to stay on single battery percentage for such a long time for no apparent reason that it feels like a misleading number.


How low does it need to get for Apple to replace? I'm thinking of getting mine replaced, but not sure if I'd notice the difference.


Under 80% and you will feel the difference if it's around 85% already.


I tried to get my wife to use the feature day one on her new 16 Pro. She turned it off that night. It was going to be too inconvenient to her.


Why? Does she drain her phone to under 20% often?


Can’t speak for OP - but yes, my wife drains hers almost twice a day due to 6+ hours of phone calls plus normal casual usage.

Probably could be more diligent with planning and charging while using near a desk, but that adds mental overhead for very little gain. Her time and mental capacity is best spent towards focusing on her extremely high stress job. The entire point of apple ecosystem is to not have to think about it.

I rarely use the 80% feature of my iwatch since I have no idea which day out of 30 or so I actually end up needing that last 20%. Not worth the extra battery towards end of life since I will very likely be trading in and upgrading by the time it’d ever be useful to me. Even a single day of not having a dead watch offsets the cost for me.

YMMV of course!


As someone who at points has had high phone call work, I found it much better to use a VOIP line with a wireless desk phone. The ergonomics are better than a cell phone, the 40-hour talk time doesn't run down my phone battery, voicemails don't clog up my cell phone, I can programatically forward the number to my cell number, etc.

Biggest downside I've found is around recording calls. I'm sure there are ways to do that with VOIP, but I've found it easiest to just use my cell when I have the occasional call I need to record.


>voicemails don't clog up my cell phone

People still use voicemails? Do you have a fax machine too?


> People still use voicemails?

In the context of a job where you're heavily using phones in the first place, yes.


Yeah, my job doesn't include phone calls at all, so it seems really alien to me now. Even so, the idea of voicemails still seems quaint and antiquated: they're incredibly inefficient for the listener. If I had a job that involved phone calls, I'd still rather just hang up when I don't get an answer, and instead send a detailed email.


In regards to the mental overhead of charging at a desk, I have found that a charging stand helps me not think about it, compared to plugging in a cable. It becomes the default place to put the phone when seated. A non-Magsafe solution might be better since there aren't cables that can be accidentally yanked.


Wow. I wonder if a non-smart phone would do better? Too bad batteries aren't removable anymore. I recall some "battery cases" that could go 48-72 hours in exchange for more bulk.


My phones are generally pretty well banged up after 18 months. If the battery lasts that long, I'm happy.


After a year, iPhone 15 - 86 cycles, 100% capacity.

I rarely let it get below 30% and don’t charge to 100%.


I just turned that off immediately. It’s not that expensive to have a shop replace the battery and it will eventually need replacing anyway. I’m not living my life at 80% and milking the battery to avoid something that is inevitable anyway. Glad to see this confirm that it didn’t do a lot anyway.


> is inevitable anyway.

The part that's NOT inevitable is it going bad during Apple's warranty window. It was such a self-serving policy to begin with. After all, the primary symptom of the kind of decay they're supposedly avoiding, is a battery with 80% capacity!




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