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Charging a lithium battery to 80% only?

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Re: Charging a lithium battery to 80% only?

#121

Post by BigJ1211 »

vbezhenar wrote: post #100
usefulcat wrote: post #27

Earlier quoted context omitted.

I've been trying a similar experiment for several years now. I have a four year old iPhone, and for most of its life, the battery level has been kept between 30% and 70%. Settings => Battery => Battery Health and Charging says that the maximum capacity is 91%. No idea whether that's better or worse than average, but I mention it so others can compare. I can say that this is the first time I've tried this experiment,…

I have 2-year iPhone 13 Mini which I didn't care much about keeping some charging regime. It reports 100% capacity. I wouldn't trust this number. Another data point: 2-year MacBook Pro 16" which lives on my table (I don't think I've ever used it without charger), keeps its battery at 80% and reports 91% capacity.

I'm on the 12 Mini without any care with charging, it's at 89% capacity. I do have "Optimised Battery Charging On" apparently, not sure when that was added? Might've always been on not sure. From the description:

"To reduce battery ageing, iPhone learns from your daily charging routine so it can wait to finish charging past 80% until you need to use it."

So I imagine it stops charging or fast charging after 80%. And slow charges that last 20% for when it expects you to need the phone. Not sure how much this differs from only ever charging up to 80%.

I also use Carplay wired, so it's always charging in the car as well.

Just checked my iPhone 11 (work phone) it's at 86%, that's the normal sized model.

Re: Charging a lithium battery to 80% only?

#122

Post by ponector »

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 ?

I don't think so. You need 20V to charge a laptop

Re: Charging a lithium battery to 80% only?

#123

Post by hrrsn »

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 ?

Probably not, seeing as that's not enough power to charge it up.

Re: Charging a lithium battery to 80% only?

#124

Post by bayindirh »

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…

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 there) or postpone charge (because the battery is used too rarely), to the list of tricks they know, and these are just the visible ones to the user.

Re: Charging a lithium battery to 80% only?

#125

Post by baq »

xvedejas wrote: post #86
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…

Because of the flatness of the voltage curve, limiting your charge to the middle range makes the state-of-charge estimation a much more difficult problem (less voltage signal). So there's actually a trade-off between longevity and accuracy of charge reporting.

iPhone 15 occasionally charges to 100% when 80% is set for this reason.

Many, many confused and complaining posts are to be found on Reddit and elsewhere about this even if it’s explained in the docs and I think next to the setting itself. It should show a notification when it goes to 100%.

Re: Charging a lithium battery to 80% only?

#126

Post by bdamm »

fragmede wrote: post #83
trustingtrust wrote: post #22

Earlier quoted context omitted.

Almost nobody cares about saving batteries. Those are replaceable and cheap to replace every couple of years. Innovating more battery life and leaving 20% battery life on the table sounds extremely pointless for what costs 20-30$ a year but lets you use the device all day instead of just shutting before the end of the day.

I'm an "almost nobody". I care about saving batteries. I get all the dead disposable vapes my friends will give me so I can recycle the batteries in them. Lithium is a limited resource and one day we're not going to have more to dig up out of the ground. There are others like me out there, I just need to find them.

Lithium is not a limited resource in the same way that Iron or Coal or Silicon are not limited. There is so much of it that we really cannot run out.

Cobalt, Neodynium and the other rare earth metals, though, those are highly valuable; and the processes to manufacture them are usually toxic. So do it for the rare earth elements, but don't do it for Lithium.

Re: Charging a lithium battery to 80% only?

#127

Post by devoutsalsa »

p1necone wrote: post #21
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…

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…

As a non-battery engineer end user, I suppose all I care about is 100% usefulness. If the phone lasts more than a day under normal operation for a few years & doesn’t get too slow, I’m happy enough.

Re: Charging a lithium battery to 80% only?

#128

Post by KennyBlanken »

actionfromafar wrote: post #118
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…

They didn’t explain what it did. The feature was amazing, the presentation misleading.

No, Samsung and others spread a bunch of FUD that Apple was crippling their phones to force people to upgrade, and Reddit and HN apple-haters ate it up.

Still to this day people on HN repeat it like it's fact, and when you correct them, shift the goalposts to "well they didn't TELL people."

Re: Charging a lithium battery to 80% only?

#129

Post by unstuck3958 »

sprokolopolis wrote: post #71

On Android, I use a terminal script called Advanced Charging Controller (ACC) to automate keeping the battery under 80% and some other battery saving tweaks. It allows you to charge to any value (like 80%), then stop charging until it discharges to another set value, which triggers it to start charging again. That was you can keep it between something like 70% and 80% while you leave it charging over night. It also h…

AccA is awesome! I used it to repurpose my decade old Samsung Galaxy Grand Prime as a custom wall clock and alarm.

I couldn't figure out how to power it without a battery, and If I had plugged it in all time I was risking an exploded battery.

Enter AccA, it remains between 50-55% all the time, along with prioritizing battery-idle mode (which means the device tries to draw power directly from the external power source).

Re: Charging a lithium battery to 80% only?

#130

Post by baq »

starky wrote: post #113
Panzer04 wrote: post #20

Earlier quoted context omitted.

Top charge in a lithium battery is very arbitrary. Most batteries can tolerate going higher than the specified 4.2v, up to 4.3 or 4.35v - but the cycle life degradation is not worth the extra capacity.

This is exactly the answer. Especially with Li-Ion cells everything is a compromise. You can extend the life of the cell by a fair amount, but then it won't last as long before you have to re-charge. Similarly, if you charge it quicker, then it reduces the lifetime of the cell. I honestly don't understand how people worry about their batteries in their devices so much. I give pretty much zero care into how I treat th…

I replace my devices when the battery wears out because I can get a new phone in 5 minutes and the battery takes a week to replace in this forsaken country.
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