swineone

Congratulations to the author for such a detailed article.

However, I've lost trust on Time Machine the software and Time Capsule the hardware. For the former, in particular, I just grew tired of having to throw backups away every few weeks and restart from scratch after the dreaded error message I'm too lazy to Google for now -- and this is even if backing up to "new" hard drives that are very unlikely to be defective. I also had a huge scare after trying to restore from a Time Machine-backed up hard drive to a new M3 Max MacBook Pro and having many, many, many (dare I say the majority) of my files missing. I simply can't and won't ever trust Time Machine again after this episode.

Currently I'm using a mixture of Carbon Copy Cloner, a GUI interface to BorgBackup called Vorta, and Arq Backup. By the way, if you have "small" amounts of data, an external high-performance SSD is something I just cannot recommend enough. I'm using the Crucial X6 (which is not super-high-performance, as there are faster models at a small cost increase) and couldn't be happier with it. I believe the diversity between mechanical and solid-state drives also reduces the chance of losing all your backups.

dewme said:

I just want to mention one thing regarding the “you cannot ignore the science” arguments.

I totally agree that you cannot ignore the science. But there is a difference between science and engineering. Engineered products are built with as much consideration for the human and societal element as they are for science. Engineers are responsible for designing products that manage the limitations imposed by the science so as not to expose users to unnecessary harm or inconvenience. This is part of what’s considered engineering margins or operational derating. 

Engineering margin is used to increase the likelihood that a product is not designed with its normal operating or rated limits too close to its scientific and physical limits. For example, if an elevator is user rated for 1000 lbs maximum, the engineers who build it and specify its operational limits will include sufficient margin to allow the elevator to exceed its rated limits by some percentage to reduce the likelihood that an overloaded elevator will suffer total failure. Additionally, a well engineered elevator will include safety devices to ensure that users cannot overload the elevator to the point of failure. 

If the batteries in these devices are in some way harmed or degraded when the user is utilizing the device within its normal, rated, and advertised limits there is an engineering design deficiency with the product. This is especially true if the user is expected to manually enforce limits/margins on their own that result in a loss in performance, capacity, or product lifetime over what the product builder sold to the customer.

If maintaining the battery charge between 20-80 percent is imperative to the health of the product then Apple should enforce these limits through derating the battery capacity and runtime that it advertises pre-sales and what it shows on the device. In this case, the percentage of battery charge remaining should reflect the amount of usable and battery-safe battery capacity available to the user based on the derated values and margins engineered into the product. This type of engineering driven product design is not beyond the capability of Apple’s product designers.

So this isn’t simply an argument about science or best practices. It’s an argument about engineered product design that considers the impact that battery rating and management has on the useful lifetime of the product. Some people may argue that enforcing engineering margins hides potential value because the batteries can actually be “pushed beyond their practical limits” when absolutely necessary, perhaps for emergency situations. I can see where an accommodation could be included to place the device into a temporary “Emergency Mode” with appropriate warnings.

In any case, I think that what Apple has done with providing the 20-80 limit is a crude admission that they didn’t do the engineering that they should have done to relieve their customers from having to worry about something they shouldn’t have to worry about. After all, not all users are scientists, they’re just ordinary folks using a product they expect to “just work.” It’s the engineers that are responsible for making that happen.

The problem is that you cannot look only at the science and engineering aspects, but also sales and marketing.

The fact is that mobile phone buyers want phones that are thin, lightweight, powerful, cheap and that hold a charge all day or even more (and when they do have to charge, they would like to fully charge it in a few minutes, not hours). And unfortunately the technology isn't there to meet all of these constraints simultaneously and comfortably. Battery technology even more so, which isn't exclusive to mobile phones or even portable electronic devices in general: just have a look at EVs.

Then there's the fact that battery runtime is a (strong) selling point, whereas very few people factor battery lifespan into the purchase. Combine this with the relationship between "overcharging" batteries and their reduced lifespan -- and really, there is no law of nature saying you have to stop charging at 4.2 V or 4.3 V or 4.35 V, all you have are different charge limit/lifespan tradeoffs. This translates into perverse incentives for device designers, who push batteries to the limit even if it means they will last a year or two (and some users don't even care since they upgrade their devices every year).

Oh, and with the drive to ever thinner devices, and users wanting waterproof phones (again a selling point), now you have to make batteries non-user-serviceable. Prior to this you would just buy a new battery for cheap and replace it. Or even keep a battery in a bag, and if you ran out of juice, you'd just replace it. Now this is impossible, and swapping batteries is much more expensive due to the labor required to take apart the phone and put it together again, much more so than the cost of batteries themselves.

So really, what was Apple supposed to do? Say they cap their batteries at the "ideal" 3.9 V (~60% of the capacity of a battery charged to 4.2 V), turning off the device once it reached the equivalent of ~30% state of charge, and remove any fast charging capabilities; this would lengthen battery lifespan considerably. But then their Chinese competitors would advertise phones with similar thickness and weight, which would last 3 times longer on a charge, and with fast-charging. Sure their batteries would last a year, two at most, but more power to them: the user would just buy a new one, providing extra revenue for the manufacturer. So Apple does what's reasonable, and just goes along with what everyone else does, which is what you would call bad design. Thankfully they've finally been waking up to this issue and adding features such as charge management, optimized battery charging and now this toggle. Of course none of this would have been an issue if they just let the owner of the phone use it as they see fit rather than according to the rules that Apple dictates; i.e. App Store rules won't let you have an app similar to Al Dente in the iPhone.

mr. h said:

Wesley Hilliard said:

M68000 said:

So, now it’s bad to charge your phone to 100% ?  Lol,  so much different information out there.  It’s hard to know what to believe. 

Simple: ignore randombro69 on a forum and listen to the experts. We've detailed what you should and shouldn't do for iPhone battery health. My recommendation will always be "don't worry about it."

Really. This whole thing is getting silly. You can't beat physics.

And I would understand all the drama if battery replacements weren't readily available and cheap.

Who’s the expert here? You? Because your article is dead wrong. It has long been well established that charging lithium ion batteries beyond 80% accelerates the aging process. It’s not the charging per se; rather just being at that elevated state of charge. That’s why the optimised charging mode attempts to wait until the last moment to bring the battery to 100%: the theory is you will start using the phone soon after it reaches 100%, thus minimising the time the battery spends above 80%. However, in my experience the optimised charging is easily thrown off if the user has an inconsistent routine so I welcome this additional control provided by Apple.

I used to try to point this out in this forum, pointing out scientific sources to this source, but every time one of the site writers came here (probably the one from this article) and always claimed it was wrong, that it made no difference, etc. To him it doesn't matter that there are all these scientific papers; Apple itself ships devices half-charged; that it offered optimized battery charging; that it now offers this setting; that Apple offers a charge management feature since iOS 11 or 12, which detect when a device is connected to power all the time (like a kiosk) and automatically caps charging at 80%; that Samsung offers this setting as well; that RC battery chargers make the express same recommendation (and usually have a "storage mode" setting); that Tesla offers similar settings and guidance (avoid charging to 100% unless absolutely necessary) on their EVs; that e-bikes/e-scooters do the same thing; and so on and so forth. No, none of this matters, after all he's a "nuclear power electrician" and we should just believe that somehow makes him an expert on the completely distinct field of battery lifespan management. Really, the writing of the current article in particular shows how desperate he is getting: "yes, Apple added a setting; trust us, you shouldn't use it, you'll gain a few weeks". Which is false, with proper charge and heat management you can, very conservatively speaking, double the lifespan of your batteries.

Now onto some of the facts:
1. Some of us don't need, on a daily basis, the full 100% charge the phone provides. We have actual work to do and cell phones are generally just toys and, in an emergency, very poor replacements for an actual work machine like a Mac or PC. Or we always have a charger close by and could in practice keep the phone charging 95% of the time, and have no "range anxiety". I for one welcome this setting with open arms.
2. With regards to point 1, if people were to keep their phones charged 95% of the time at 100%, this would have definite effects on battery lifespan. On the other hand, with this setting, batteries could last much much longer.
3. When we do need the full charge, we can just toggle off the setting temporarily. Best of both worlds.
4. Heat is the #1 killer of batteries, especially combined with high state-of-charge. You have people who spend most of their day in a car, sometimes with the phone in direct sunlight, and charging to 100% all the time. I'm impressed that under such conditions a phone's battery would last a year. Now change that to charging to 80%, and suddenly the battery has a decent chance of lasting years.

Now onto the next fallacy: "just replace the battery, it's cheap". Here's a few other facts:

1. The world is not America. Where I live, changing an iPhone battery costs a significant portion of a month's minimum wage. I of course make more than the minimum wage, but it is proportionately expensive to myself. And pray you have an Apple store or an Apple authorized repair shop where you live; I live in a city of ~500,000 people and there wasn't one here until a few years ago. In my whole country, one of the largest on earth, with over 200 million people, there are only 2 Apple stores. 90% of the country is hundreds of miles away from the nearest Apple store. In fact a large percentage of the country is over 1,000 miles away from the nearest Apple store.
2. This leads people (even in America) to change batteries on unauthorized resellers in these phone-fixing kiosks you now find everywhere. Since Apple doesn't sell the batteries they use to the public (including these kiosks), you're taking a gamble on the lowest-bidder type battery, with awful performance and even risk of swelling and explosion.
3. Apple loves to claim how they're eco-friendly and so on. Well guess what's better than recycling a battery? Not swapping a battery at all! But of course in that case there's no money to be made swapping the battery or, even more convenient to Apple, swapping the device as a whole for a brand new iPhone.
4. To finish off, Apple may just plain refuse to swap the battery for you. I have a personal experience with this, on a 10.5" iPad Pro. The battery has been severely degraded, both as indicated by Coconut Battery, and from monitoring runtimes (much, much less than when it was new). I was in Abu Dhabi this year and took it to the Apple store in Yas Mall, asking them to change the battery for the price quoted on the website (459 AED, about US$ 125). Their reply, later confirmed by a call to the UAE Apple call center: "it's impossible to change the battery on an iPad, so we have to change the whole device and we charge much more [over 1200 AED as I recall] -- unless our [opaque] diagnostics claim that it reached the magical <80% threshold, in which case we'll replace it for 459 AED". Well now they run this opaque diagnostic and voilà, like magic, it claims my battery is at 90%, which disagrees with both Coconut Battery (which claimed <70%) and my actual experience. For all I know this opaque diagnostic software just outputs a random number over 85% to ensure they never agree to letting you pay the 459 AED price. Never mind that this information isn't given on this page or anywhere else. So you buy an iPad, safe in the knowledge that whenever you're not happy with how long a charge lasts, you can just pay 459 AED to replace it. Then when you go exercise this "right" you thought you had, suddenly it's 1200 AED price. Really slimy tactics from Apple.
5. By the way, a battery for the 10.5" iPad Pro costs US$ 25 at iFixIt. I'm pretty sure they sell decent batteries, although I'd rather have the Apple original one. And that's retail price, from a company that buys them in small quantities -- compare to Apple buying at gargantuan quantities with tailormade purchase contracts. So it's pretty clear that Apple is making a decent amount of cash on these battery replacements. And also, the claim by the Apple store that "it's impossible to replace the iPad battery" is blatantly false: iFixIt has a guide showing how to do it, and I've asked many of these phone-fixing kiosks and they will swap it if I want. In the end I just went with a new iPad (see, Apple's strategy of planned obsolescence worked perfectly with me) and will sell the old one to someone who will just swap it for a lowest-bidder battery and risk setting fire to their house. Oh well, at least it's their house, not mine.

Driving habits and temperature also affects aging, a characteristic that came to light when EV batteries operating in a warm climate faded prematurely. It was learned that keeping a battery at elevated temperature and high state-of-charge causes more stress than aggressive driving. In other words, keeping a fully charged Li-ion at 30°C (86°F) and above hastens the aging process more than driving at a moderate temperature.

Ooh, I only wish I had mentioned previously that high temperature and high SoC destroys batteries... wait, I did! Only to be called a troll by some "microelectronics-research-engineer-turned-iOS-developer" who, get this, doesn't even know what state of charge is!

Harsh loading also reduces battery life. Because of its large size, the EV battery is only being stressed moderately, even during acceleration. In comparison, the mobile phone draws continuous high current from a small battery when transmitting and crunching data. This puts more stress on a mobile phone battery than driving an EV. A battery is also negatively impacted by the pulsed load of a mobile phone rather than the DC load of an EV.

Now we finally come to something we can't work around, right? I mean, drawing continuous high current, pulsed loads, etc. Except, perhaps, maybe, just maybe, if we could leave the phone plugged in all the time so that these loads are placed on the charger rather than the battery. Well, it'd be great to do that, so long as Apple provides a blessed API call and approves an app to limit charging, since otherwise leaving the phone in the charger all the time will keep the battery at 100% (you know, the concept that doesn't really exist according to our microelectronics research engineer friend, of high SoC?) and as we just established, that destroys batteries, even more so when combined with high temperature.

Well, I just finished reading the article and was unable to find why a mobile phone battery that is: 1. connected as often as possible to a charger with a charge limit in place of say 60 or 70%, 2. avoids heat, 3. avoids fast charging (all as stated in my first post) should last less than an EV battery -- in fact it should last more.

But maybe I'm wrong. If that's the case, please quote the exact sentence or paragraph from the article that contradicts the above statement. I'm done with the "EV batteries are just different" sleight of hands from people that couldn't point out where lithium is on the periodic table if their life depended on it.

ilarynx said:

Also, if this were an Apple conspiracy thing, you'd be comparing Apple's phones with another phone manufacturer. Instead, you take the apples v oranges approach of comparing the very small, single-celled phone batteries with the much more massive multi-celled EV batteries. 

As has been noted, there are limits of physics and chemistry that cause batteries to behave the way they do. You can read about why EV batteries last longer than phone batteries here (spoiler - it's not an Apple conspiracy):

https://www.google.com/search?client=safari&rls=en&q=batteries+ev+and+phone&ie=UTF-8&oe=UTF-8

Great, let’s stick to the facts. As a scientist that’s what I love to do. So let’s grab some excerpts from the second page that shows up on that Google search.

EV advocates may argue that a smartphone battery cannot be compared to an EV battery; these products are totally different. That is true, but ironically both use lithium-ion systems.

So OK, we start by establishing that we’re talking about the same chemistry. Quite obvious, but perhaps it needs to be said do some.

A mobile phone gets charged at the end of a day and the stored energy can be fully utilized until the battery goes empty. In other words, the user has full access to the stored energy. When the battery is new, the phone provides good runtimes but this decreases with use. In this full cycle mode, Li-ion delivers about 500 cycles. The user adjusts to the decreasing runtime, and being a consumer product, the end of battery life often corresponds with a broken screen or the introduction of a new model. Built-in obsolescence serves well for device manufacturers and retailers.

Ooh, did he say “built-in obsolescence”? Probably just another troll like myself. After all, we all know for a fact that there is no such thing, and anyone saying otherwise is self-evidently a troll. Never mind if you’re a scientist, or someone who built a successful company around battery management and ran it for decades.

Back to the facts though. “A mobile phone gets charged at the end of a day and the stored energy can be fully utilized until the battery goes empty. In other words, the user has full access to the stored energy.” Funny, that’s exactly what I’m claiming breaks the battery. Guy must really be a troll. Anyway, so if we could work around that standard usage pattern and, I don’t know, limit charging to 60 or 70% SoC all the time, like I’ve been suggesting, and keeping it plugged in all the time, I wonder what would happen? Maybe we would get closer to the EV charge/discharge model and thus to the EV battery lifespan? Nah, impossible.