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Charging a lithium battery to 80% only?

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Re: Charging a lithium battery to 80% only?

#131

Post by vladvasiliu »

tjoff wrote: post #74
p1necone wrote: post #21

Earlier quoted context omitted.

I'm pretty sure most (all?) manufacturers already do (the first part of) this. 100% can't be the point at which the battery literally stops taking new charge - if you did that they'd catch fire all the time. It's just that the manufacturers idea of what "100%" should be generally skews more towards the immediate battery life end of the tradeoff, whereas some users prefer to have "100%" closer to the maximizing long t…

You are right but I disagree. Yes, devices do not charge batteries to 100% as that is directly damaging. And they don't discharge to 0% for the same reason. So they charge to something slightly less. But that slightly less is for all intents and purposes the only definition of 100% we, as end users, have. It's like saying that your CPU is actually only running at 70% clock frequency but overclocking it to 100% would…

While I agree with your general take and hate that my iphone can't be capped to 80% [0], and love that my otherwise crappy hp laptop can be capped to something like 85% (and reports both cap and max capacity), I don't agree with your final take.

To take the phone example, mine usually ends the day around 85%. I just don't use it too often. But I sometimes absolutely do and would trade months of battery life for not being left without battery in the middle of nowhere. And the 20% can make all the difference.

A few years ago, I rented a car in a foreign country on a foreign continent. It didn't come with a USB port, and I didn't have a cigar adaptor. When I arrived at my destination, at night, my phone's battery was 10%. I sure as hell am happy that it was charged to a "full" 100% instead of dying on me one hour earlier.

Sure, I could have grabbed an external battery or something. Not sure how much environmentally smarter that is, since it would basically rot away in a drawer somewhere, since I would basically never use it.

---

[0] Where does this 80% come from? Would it be even better if I stopped charging at 60%? I rarely use more than 20% of my phone's battery, so that would be largely enough, but I sometimes absolutely do and would hate to have to lug around external batteries "just in case".

Re: Charging a lithium battery to 80% only?

#132

Post by The_Colonel »

jader201 wrote: post #102
Dylan16807 wrote: post #40

Earlier quoted context omitted.

> So I just leave them plugged in Isn't that exactly why you want a device that can self-limit? It doesn't need to lie.

If you leave it plugged in all the time, battery life doesn't matter. Self-limit or don't. I'm rarely away from a power source for very long (and when I am, I'm not on my phone much). So I just leave it plugged in all the time. I've very rarely had my battery die on me, and like OP, I leave mine plugged in all the time. At night or while working, it's charging. Even after a few years, I don't notice much of an impact…

> At night or while working, it's charging.

It doesn't have to be charging all the time. Some laptops have "intelligent" detection of the "usually plugged-in" state and won't keep the battery charged 100% at every moment, but will allow dropping it somewhat before charging again.

I suspect MacBooks are doing this quite aggressively (while lying about 100%), since their batteries tend to last (in terms of cycles) longer than windows laptops.

Re: Charging a lithium battery to 80% only?

#133

Post by _cenw »

dandy23 wrote: post #107
hilux wrote: post #79

Earlier quoted context omitted.

It's well-established that iPhones have longer average lives than Android phones.

Really? If that is true, I wonder how much is due to the fact that the phones are more expensive so people take care of them more or delay their next purchase. It's not because the actual quality would be better. If you pull statistics you also have to filter out the sub 150 dollar Andoid phones which may well have shorter average usage life.

Software support is an important one, and Apple has managed to slow down the RAM baseline inflation that Android seems to experience every other year. Even people who regularly upgrade usually trade in their old phones because they still have enough value to bother, so a lot more phones get used all the way to the end of their support.

Re: Charging a lithium battery to 80% only?

#134

Post by KennyBlanken »

pmontra wrote: post #99
arcanemachiner wrote: post #70

Earlier quoted context omitted.

Yeah but then you have to buy an iPhone. That's not snark. I want things from my phone that an iPhone can't give me. The battery replacement ecosystem in Android land is pretty dismal.

It depends on your definition of dismal. Any phone repair shop can open phones and replace batteries. There are also disassembly videos for most models on YouTube. I looked at them, ordered parts and replaced the battery on my Samsung A40 when it started to discharge too quickly. I also replaced the camera after a hard crash on the floor broke the autofocus. Maybe not having Samsung shops makes all of that dismal but…

Market fragmentation among Androids means that nobody stocks parts for anything and the margins are so low, a lot of shops will only do the brands they want to.

I couldn't find anyone to replace the battery in my Google Nexus phones, every time I tried, in a major metropolitan area. Ended up having to do it myself.

You can walk into nearly any cell phone shop in the world with an iPhone and walk out with a replaced battery because the staff know them and they stock parts for them.

Re: Charging a lithium battery to 80% only?

#135

Post by Reason077 »

rekoil wrote: post #116
belltaco wrote: post #14

I wish they would label it so that it shows 100% charge when it's actually charged 80%, and then give an option to 'overcharge' a configurable amount till 125% (the current 100%). That way it will make people aware that they are reducing the battery life by overcharging, and be picky when they overcharge. But this won't happen because reduced battery life is a big direct and indirect(by reducing performance like Appl…

> by reducing performance like Apple does with old iPhones What Apple did was clock down the CPU of iPhones with degraded batteries in order to reduce peak load which would otherwise result in crashes that would have made the device borderline unusable below some charge percentage. Yes, they should have shipped the feature off by default and with a toggle, but the feature itself was amazing as it let already old phon…

> "What Apple did was clock down the CPU of iPhones with degraded batteries in order to reduce peak load"

It wasn't what Apple was doing that was the problem, it was the fact that they were initially quite secretive about it! People just started noticing their phones slowing down without explanation. Now days iOS tells if your battery no longer supports peak performance, which is the right thing to do.

> "Yes, they should have shipped the feature off by default and with a toggle"

Oh, it should always have been on by default. Most people would much rather their phone run a little slower than risk random crashes and shutdowns! But iOS should have told you about this from the start.

Re: Charging a lithium battery to 80% only?

#136

Post by pkolaczk »

bayindirh wrote: post #124
rekoil wrote: post #116

Earlier quoted context omitted.

> by reducing performance like Apple does with old iPhones What Apple did was clock down the CPU of iPhones with degraded batteries in order to reduce peak load which would otherwise result in crashes that would have made the device borderline unusable below some charge percentage. Yes, they should have shipped the feature off by default and with a toggle, but the feature itself was amazing as it let already old phon…

Apple's know-how in battery management is always a couple of generations ahead of its closest competitor. My 2008 MacBook Pro was able to detect battery problems one year before they started to manifest physically. They did it by adding another controller and an independent firmware to the battery itself, but there was no better tech at that time. M powered MacBooks added auto hold-off (discharge to 80%, keep it ther…

> discharge to 80%, keep it there

Where? AFAIK this is a feature you need a third party app like Aldente for. The OS does not offer any way to control battery charging level. Yes, it tries to be smart and guess when you need full charge and sometimes decides to charge to only 80% but that doesnt work for all users except the ones with very regular routines and there is no manual control.

Re: Charging a lithium battery to 80% only?

#137

Post by The_Colonel »

Samsung phones have a good feature which limit charging to 85%. The only thing it's missing is the easy "I want full charge today" button, you need to go deep into settings to toggle this.

The other minor annoyance is that subjectively the battery charged to 100% seems to make a bigger difference than the reported 15% indicates - it seems like 30% or even more. Maybe some battery recalibration issue. But it doesn't bother me that much since 85% still carries me comfortably through the day.

Re: Charging a lithium battery to 80% only?

#139

Post by euroderf »

euroderf wrote: post #97
usefulcat wrote: post #65

Earlier quoted context omitted.

I wish I did but I haven't found one yet. I'm at my desk a lot, and that's usually when I charge it. I mostly use an old, low-current charger (originally for a bluetooth headset) so it charges slowly, about 5% per hour.

Which begs the question: if I charge my new Mac with an iPhone charger (8W), will it lengthen the battery life ?

Answering peer comments: oh but it DOES work.

I forgot my charger in another town so I bought a USB-A/C cable and tried it out. Again, the iPhone charger is 8W. This is also the value reported by '/usr/sbin/system_profiler SPPowerDataType | grep Wattage'

When the Mac is open and in use (2023, M2) the iPhone charger can just about keep the charge level level, depending on usage.

But then when I close the Mac, it can easily take 10 hours to reach a full charge... but it does hit 100%.

So I am wondering if this is in fact a gentler way to charge the battery.

Re: Charging a lithium battery to 80% only?

#140

Post by apexalpha »

glandium wrote: post #108
artimaeis wrote: post #16

Earlier quoted context omitted.

I just picked up my 2017 iPad Pro. It was last charged Nov 15. Been sitting by the bed mostly unused since. Currently at 80% charge. I haven’t experienced what you’re describing on an Apple device since they switched the laptops away from Intel chips. In my experience, the OS does matter. I can’t believe how bad the rest of the industry is at this. Amazon’s Kindle line is incredible at this IME, but those are pretty…

I have the exact opposite experience. My 2013 MBP can keep its charge for months while suspended/hibernated. My first-gen M1 MBA will deplete the battery in a week under the same conditions.

My M2 Air will sit comfortably for weeks with little depletion at all. It's the only laptop I've ever owned where I comfortably walk out of the door without a charger with 35% battery.
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