Apple have "invented" a new way of charging LiPo batteries in phones?? - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: July 18, 2019, 11:00:21 am
content: Apparently Apple have come up with "Optimised Battery Charging" as of IOS 13. From what I can gather, they are trying to suggest that charging (and keeping) a Lithium battery at 100% is bad.I don't profess to be a battery expert and please correct me if I'm wrong, but my understanding of most modern phones, laptops, tablets and other Lithium-based devices is this:- Lithium batteries aren't "float" or trickle charged at the end of their charging cycle like NiCd or Lead Acid batteries, once the're full, charging is suspended and there is no risk of over-charging.- Once the battery is fully charged, the device itself is powered by the charging cable (until such time it's unplugged and switches over to battery).- Lithium-based batteries prefer shallower discharge/charge cycles. So if you run your phone to about 50%, you should top it up as opposed to letting it run low.Has Apple actually improved things or is this just marketing wank?Source:https://www.macrumors.com/2019/06/05/ios-13-optimized-battery-charging/

author: Psi
author_rank: Super Contributor
timestamp: July 18, 2019, 11:18:06 am
content: It has been common knowledge for many many years that lithium batteries do not like being at 100% charge or 0% charge.Anyone who flys RC aircraft knows this effect very well because the lithium polymer type cells we use are very susceptible to this issue.We store all our batteries at whats called "Storage charge" about 3.8V per cell and approx 40%We have to charge them up to full the day before we fly and put them on the battery charger set to "storage change" mode when we get home. This returns them to 40% before we putting them away for a flight another day.Model RC batteries left stored at 100% charge for a month are almost ruined, they somewhat loose their ability to supply burst of high current.Electric cars, like the tesla, use lithium ion cells but they still do not like to be full or empty. They actually have a user configurable option via the touchscreen to make the car pretend its battery capacity is less than it really is, Like maybe you set it to use between 30% and 80% of the battery.This allows you to get better longevity out of your car before the battery pack needs replacing.So Apple are just doing what they always do. Pretending something is unique/new when its not.

author: ogden
author_rank: Super Contributor
timestamp: July 18, 2019, 11:49:52 am
content: Quote from: Psi on July 18, 2019, 11:18:06 amRight. Apple is kinda late hereNot only RC hobbyists knows that. Android (part of) community knows about battery health issues, there are many articlesthis for example. My quite old Android phone have "battery life extender" function which actually charges to 90% while saying that battery is full. There are some laptops with same option, dunno maybe it is even Win10 function nowadays.

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 18, 2019, 12:04:21 pm
content: yup samsung and probably others with android phones already did this in background much earlier without making this as a buzz feature, i guess as the original battery can last for many years. while buying my galaxy A7 last year, the sales person also promoted to me another china brand, oppo or huawei cant remember that has this feature specifically and configurable in OS GUI. so either they have the technology or not, it doesnt really matter as smartphone model can obsolete much earlier than the battery life... and yes btw, as a noob RC wannabe, i learnt this the hardway, stored LiON in full charge and within a year it bulged and died prematurely before being put into real good use

author: filssavi
author_rank: Frequent Contributor
timestamp: July 18, 2019, 12:38:55 pm
content: If any of you managed to reed the actual article, the new feature has nothing to do with how the battery get's charged, but rather when...The idea behind this is clearly that since everyone attaches the phone to the charger when they go to bed and wakes up at a very predictable hour in the morning, instead of charging the battery to the max right away they charge it only to 70/80% and then in the morning just before wake up they top it off to 100%, so the battery doesn't sit all night at 100% and this should reduce wear.On the top of my head I don't know of any android phone that does this

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 18, 2019, 12:45:56 pm
content: "Invented". YeahIt's been a known fact for over ten years. You can find a few papers out there. Basically the max number of charge cycles of a LiPo/Li-ion battery decreases as the max battery voltage increases.The voltage at ~80% SoC (I think something around 3.92V for the average battery) is often considered a good compromise between the gained battery life and the lost capacity. Another benefit for the user is a reduced charge time.You will also notice that the phones will be getting bigger and bigger to accomodate larger batteries to make up for that.One thing to note is that the battery voltage *while* it is charging is not that good an indicator of the SoC. The open-circuit voltage is a better indicator AFAIK. This is not a problem when fully charging the battery, as the normal charge cycle is made of a constant-current, then constant-voltage at 4.2V and the end-of-charge is detected when the charge current in constant-voltage mode drops below a few % of C. If you're only charging it up to ~80%, you usually won't be in constant-voltage mode and estimating the SoC in that condition is much less accurate IMO. Of course a given device manufacturer can calibrate/model the battery in said device so they can be not too far off. Just saying though that if fully charging the battery, its OCV will indeed be pretty close to 4.2V, whereas if charging it only partially, thus reaching a lower voltage, once the charging is stopped, its OCV after just a couple seconds to a couple minutes can drop significantly, so IMO a decent model is definitely required to do this reliably if you really want to get a 80% SoC.

author: ogden
author_rank: Super Contributor
timestamp: July 18, 2019, 01:00:10 pm
content: Quote from: filssavi on July 18, 2019, 12:38:55 pm"Battery care" function, AFAIK introduced with Xperia X (compact) Sept 2016, later other and also older models got with FW update:https://support.sonymobile.com/us/xperiaxz/userguide/battery-and-power-management/.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 18, 2019, 01:03:06 pm
content: Quote from: filssavi on July 18, 2019, 12:38:55 pmIndeed. We've been a bit quick thinking that they were merely doing what had been already known and discussed for years.They chose to leverage that knowledge without compromising the overall capacity. That's still based on the same facts.I have seen numerous studies showing the relationship between the max number of charge cycles and the max voltage, but I don't think I have seen any that takes the "time sitting at over xx V" into account, especially if we are just talking about a couple hours. No clue if it would really make a difference, or if merely charging the batteries to 4.2V even if they don't stay at 4.2V for very long is the main factor...Quote from: filssavi on July 18, 2019, 12:38:55 pmI don't either. But again, I'm not completely sure it is effective. It's a pure software feature that probably took only a few hours to get done, I don't know if they filed a patent for that (I'd suspect they did!), in which case handling the patent is likely what took them the most time here...

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 18, 2019, 01:06:04 pm
content: Quote from: ogden on July 18, 2019, 01:00:10 pmI've never used a Sony mobile. Didn't know. So does that mean that this "invention" is thus actually not patentable? Apple would probably not have done it if it weren't. They must have found something revolutionary about the use and charge patterns of the users so they could still patent it.

author: ogden
author_rank: Super Contributor
timestamp: July 18, 2019, 01:19:28 pm
content: Quote from: SiliconWizard on July 18, 2019, 01:06:04 pmPatent? Which one? Article does not mention "invention" nor "patent". Anyway I find it strange that Apple introduces function that prolongs expected lifetime of it's products. By saying so I mean BatteryGate:https://www.ifixit.com/News/batterygate-timeline. It blew-up in their face and now they are nice to customers or what?

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 18, 2019, 01:38:43 pm
content: Quote from: ogden on July 18, 2019, 01:19:28 pmI didn't say the article did mention a patent.I'm just saying that pretty much any new feature Apple introduces gets an associated patent. So for Apple not to patent this one would be a huge surprise.

author: filssavi
author_rank: Frequent Contributor
timestamp: July 18, 2019, 03:12:25 pm
content: Quote from: ogden on July 18, 2019, 01:00:10 pmGood to know, honestly I had only samsung and motorola's before switching to iPhone, and for sure they didn't do thatAlso Dare I say that nowere in the original article is claimed that this is an apple invention, innovation, patent or exclusive feature, the article simply states that the feature will be introduced and explains how it works.

author: langwadt
author_rank: Super Contributor
timestamp: July 18, 2019, 03:30:04 pm
content: I think Lenovo laptops a have had the option to optimize battery lifetime by only charging to 80% for a long time

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 18, 2019, 03:56:38 pm
content: Quote from: filssavi on July 18, 2019, 12:38:55 pmdoesnt matter. apple can make mud collecting bee buzzing sound on this all over but yet it still doesnt matter as battery life on another android phone can live longer after the phone is considered obsolete, in case it needs battery replacement, it can be had for 10-30$ in any shops. try that with obsolete iphone model. go to apple booth... sorry we dont sell that model anymore, you go to get compatible part from china, be ready to get sued for copyright infringement. go watch rossman videos thats what he told...

author: Psi
author_rank: Super Contributor
timestamp: July 18, 2019, 11:53:57 pm
content: Quote from: filssavi on July 18, 2019, 12:38:55 pmyes but this is obvious and nothing that anyone should be able to say they "invented"

author: Halcyon
author_rank: Unknown
timestamp: July 19, 2019, 01:03:38 am
content: Quote from: filssavi on July 18, 2019, 12:38:55 pmMy 5+ year Android handsets still hold most of their capacity and I've always left them charging overnight, every single night. Perhaps they just have a properly designed and developed charging capability and it happens in the background without the user knowing. 100% on the display might actually be 95% SoC in the battery. *shrug*

author: TK
author_rank: Super Contributor
timestamp: July 19, 2019, 01:17:43 am
content: Is the same strategy recommended by Tesla... charge up to around 70-80% for daily use, then charge 100% 1-2 hours before a long trip... and never let it drain to 0%Apple is claiming that they "invented" the optimized charging on the iPhone, so it is a genuine claim. They are not saying anything about all the other battery powered devices...

author: coppice
author_rank: Super Contributor
timestamp: July 19, 2019, 01:23:01 am
content: I thought Apple had always avoided the battery spending too much time at 100% charge by running it down really fast in normal use.

author: james_s
author_rank: Super Contributor
timestamp: July 19, 2019, 01:57:16 am
content: Quote from: Psi on July 18, 2019, 11:18:06 amHeck I never charge batteries the day before I fly, I usually toss a set on the charger while I'm packing up my gear and loading planes into the car, then when I get to the field I put another set on the charger while I fly the set I charged at home.In the context of phones I suppose this is unique and new though, every phone I've had fully charges the battery when plugged in. My Lenovo laptop does have a mode that only charges up to 87% though.

author: all_repair
author_rank: Frequent Contributor
timestamp: July 19, 2019, 04:11:51 am
content: Just wondering for how long does a phone stay at 100% charge, probably very little of the time unless it is a store-away phone. The time below 20% is the actual killer IMHO.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 19, 2019, 01:12:16 pm
content: Quote from: coppice on July 19, 2019, 01:23:01 amAs I mentioned earlier though, I am personally not convinced that this "optimization" strategy actually gets you more charge cycles (even though it is said that Tesla did something similar, that's still not a scientific study). I suspect that merely charging up to the max voltage already reduces the total number of charge cycles, however short a time it spends at this voltage (except maybe if it's VERY short). I'd be interested in seeing a proper article with actual measurements and statistics proving that this "last moment" strategy actually improves things at all.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: July 19, 2019, 01:27:56 pm
content: How does it know at what time are you going to wake up?

author: Jeroen3
author_rank: Super Contributor
timestamp: July 19, 2019, 01:38:54 pm
content: You need to look a bit further here.Apple needs some way to explain to users why their battery fails early, or the phones throttles down, in the coming iPhones. You know, they had this issue a while ago where phones ran slower with older batteries and such.So instead of doing nothing, they "invented" a "revolutionary" charging algorithm that "detects and learns your life" to "optimize charging" or something with lots of buzzwords.In the end little changes and they just present a checkbox to users that disables the longevity cap and moves liability for early failed batteries away from Apple.Batteries are the only thing that limits what phones can do. They are run at the edge. The only thing to do now is using larger batteries, but then Mr Ive wouldn't like the design anymore.

author: Mr. Scram
author_rank: Super Contributor
timestamp: July 19, 2019, 01:41:13 pm
content: It should also be noted that the definition of what constitutes a 100% charge is pretty much arbitrary. Stuffing more energy in a battery causes it to wear more and setting a more conservative 100% will lead to more cycles but less charge per go. In space constrained designs like smartphones the choice will generally be stuffing in as much charge as you can at the cost of reducing the longevity of the battery.

author: ogden
author_rank: Super Contributor
timestamp: July 19, 2019, 04:50:48 pm
content: Smartphone usage patterns differ and phone upgrade interval differ as well. For those who do not lick their phones non-stop whole day and/or do not upgrade to new model every year, battery life extender function could be helpful. I agree that most users who wake-up with alarm clock will be fine with function Apple just introduced, yet for me 90% charge worked for couple of years well, battery still is in good shape and I never experienced "anxiety of battery low" with my current phone.

author: stevelup
author_rank: Regular Contributor
timestamp: July 21, 2019, 02:32:40 pm
content: Quote from: GeorgeOfTheJungle on July 19, 2019, 01:27:56 pmIt looks at your alarms / calendar etc, and failing that, statistical data. I don't have any alarms or calendar entries for the weekend, but it tells me it'll be holding off the 100% charge until just before I wake up, and the time it chose for when I was going to wake up was spot on.I suppose if you suddenly get up hours early with no alarm, or nothing in your calendar to suggest you're going to be getting up early, then you might wake up to an 80% charged phone.It seems pretty smart to be honest.

author: ogden
author_rank: Super Contributor
timestamp: July 21, 2019, 03:00:21 pm
content: Quote from: stevelup on July 21, 2019, 02:32:40 pmRight. Alarms are just "hints" for decision making. Phone analyzes it's usage patterns for, let's say, each quarter hour of the day, gather used/not statistics for recent week or two or three. In the end it can guess when you need your phone pretty well unless you suddenly break your usual daily routine. Even then you end-up with 80% charge which is not deadly at all.

author: David Hess
author_rank: Super Contributor
timestamp: July 22, 2019, 02:43:06 am
content: Rechargeable lithium cells wear out in the same way as other battery technologies. Some reactions result in products which lock away the materials which take part of the charge and discharge process.In the case of lithium batteries, high voltage increases the rate of these side reactions so there is some function like every 0.2 volt increase decreases operating life by half or something. I do not remember the exact numbers. Optimum operating life ends up being at about 2/3rd capacity depending on how the battery was rated.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 22, 2019, 08:41:36 pm
content: Quote from: Halcyon on July 18, 2019, 11:00:21 am"Bad", not in a sense of immediate destruction or anything like that, but yes, somewhat increased degradation rate.This has been well known for at least two decades.About a decade ago, everybody finally implemented this feature.So I guess Apple is a bit late to the party.Or maybe their marketing has just recognised that it's been long enough since this feature was sexy, so everybody's forgotten about it already and it's a fancy new feature again, like it was in 2010?

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: August 15, 2019, 07:48:41 pm
content: Quote from: SiliconWizard on July 19, 2019, 01:12:16 pmAnother reason not to charge a Tesla (or any EV, for that matter) to 100% is regenerative braking. Charge it to 100% and you loose regen braking because the current generated by the motor acting as a generator has nowhere to go. Sure, you could burn it up in a resistor bank, but there are drawbacks to that too.

author: ogden
author_rank: Super Contributor
timestamp: August 15, 2019, 08:56:33 pm
content: Quote from: Sal Ammoniac on August 15, 2019, 07:48:41 pmProblem you described will happen in very, very rare case when you miraculously (downhill?) accelerate without using battery charge. As long as you accelerate discharging battery, regenerative braking return less than it is spent to accelerate. It's law of conservation of energy + nothing is perfect in this world law.