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The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

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Re: The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

#161

Post by Dylan16807 »

jauco wrote: post #152
Dylan16807 wrote: post #140

Earlier quoted context omitted.

Right, once overnight is ending. It only optimizes overnight, with the battery limited the vast majority but not right at the end. I don't see the conflict.

It doesn’t work if I plug my phone in at 9am in the morning. It will charge my phone to 100% immediately in that case. Even if I leave it connected to power all day. Breaking my battery. Optimized charging is based on learning and thus unpredictable and hard to influence. It only works if you have rigid habits.

The article says it only works in that situation, not that being in that situation is a guarantee of it working. I think the phrasing is fine. Do you disagree?

Like, if I say my car only starts when it has gas, I'm not promising it always starts as long as it has gas.

It's far from a comprehensive list of things that break the feature, but it gets the point across that the existing feature does a fraction of the job at best.

Re: The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

#162

Post by Scoundreller »

gnicholas wrote: post #148
Casteil wrote: post #147

Earlier quoted context omitted.

That's the original intent, but there's nothing stopping you from enabling it whenever to try to get the absolute max possible out of your battery. Low power mode does sacrifice quite a bit of functionality by default though. Personally, my 15 pro can do >72 hours on a single charge WITHOUT doing stuff like this, even starting at 80% (note: mostly standby, no always on display, with ~3h screen on time total). The 80%…

Oh sure, I put my phone in LPM sometimes when I know it's going to be a very long day. But why would someone put it in LPM when it hits 90%? Is that referring to when it charges up to 90%, or when it's in use, unplugged, and is "down to 90%"?

The latter.

For me, I find the performance/lost functionality fine: https://support.apple.com/en-ca/HT205234

Re: The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

#163

Post by zootboy »

publicmail wrote: post #93
zootboy wrote: post #68

Earlier quoted context omitted.

The world of lithium-ion battery chemistry is quite complicated, but in my experience, the top contributors to battery wear-out are, in decreasing order of severity: - Charge cycles (including partial cycles, e.g. 100% -> 50% is half a charge cycle) - Depth of discharge (deeper discharge cycles are worse) - Extended periods in hot conditions (over 40 degrees Celsius) - Extended periods of being held at 100% state of…

I think another huge killer of lithium batteries is charging them when below freezing. I bet most phones probably wouldn’t allow it though - or at least would limit it.

I left out things that a typical battery management system will prevent, like over/under charging, or operating outside safe temperature limits. But yes, charging a typical cell below 0 degrees Celsius will immediately and permanently damage it. Here's a ref with some details on why:

https://www.bonnenbatteries.com/lithium-battery-low-temperat...

Li-ion chemistries that are tolerant of charging at low temperatures are a subject of active research.

Re: The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

#164

Post by wrboyce »

Scoundreller wrote: post #162
gnicholas wrote: post #148

Earlier quoted context omitted.

Oh sure, I put my phone in LPM sometimes when I know it's going to be a very long day. But why would someone put it in LPM when it hits 90%? Is that referring to when it charges up to 90%, or when it's in use, unplugged, and is "down to 90%"?

The latter. For me, I find the performance/lost functionality fine: https://support.apple.com/en-ca/HT205234

On the other hand, I’ve pretty much stopped using LPM after getting a 14 Pro and getting used to the higher refresh rate of the ProMotion display; I find the slower refresh rate really jarring (I also have a non-Pro 14 which I don’t like using for the same reason).

Re: The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

#165

Post by numpad0 »

manwe150 wrote: post #120
numpad0 wrote: post #104

Earlier quoted context omitted.

Limiting charging to 80% means getting rid of constant voltage charging mode altogether. Generally speaking and in illustrative numbers, Li-ion batteries are charged in following manners: - Below 10%, battery is charged in pre-charge mode through a 10-foot pole. - Above 10%, battery is charged in constant current mode, as in: `charger.current_max(battery.CAPACITY * battery.CHARGE_C_RATE)` `charger.voltage(battery.vol…

It is not fundamentally possibly to simultaneously set voltage and current of the charger as they are inversely related to each other and vary as a function of charge state. As the battery gets more full, the current is forced to decrease as the battery resistance increases (or equivalently the voltage is forced to decrease, or some combination of the two). So those given parameters seem to be more estimates of the c…

That is principally correct, and, in fact, a fixed voltage power supply with a resistor in series just works for charging NiMH/NiCd, yes.

In Li-ion however, I think it's something like, max voltage ramp is limited even within current limit, then afterwards current is limited even below cutoff voltage, or whatever to similar effects. It's definitely more complicated than just constant max voltage fed through a 330R.

Re: The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

#166

Post by timrichard »

TheMiddleMan wrote: post #25

Related: for MacOS, AlDente allows you to set a battery charge limit. https://apphousekitchen.com/ I've been using it successfully for around a year. It works pretty well sans a couple quirks due to hardware limitations e.g. if you plug in with the screen closed (sleep mode) it will charge fully to 100%.

That's true. I evaluated it, but it wasn't of use to me as I keep my Macbook plugged in with the lid closed.

I eventually tried this instead (for Intel Macs) :

https://github.com/DevNulPavel/osx_battery_charge_limit

I use it to keep my battery level indicator pegged at 70%. Often doesn't persist after a system update, but it's just a quick terminal command to reapply the setting.

I use my Macbook in clamshell mode, and I use sleep mode when I'm not using it - receiving power from a Thunderbolt dock. It's handy to pick up exactly where I left off on resume. Plus, I use two LG screens where one of the two doesn't switch on after a cold boot, and it's annoying to unplug and replug to activate it. Sleep mode gets around that.

Re: The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

#168

Post by Reason077 »

stealer0517 wrote: post #118
grepfru_it wrote: post #106

Earlier quoted context omitted.

10-20% will definitely reduce cycle life. you would almost double your cycle count by keeping your battery above 40% vs 20%

Cycle count is virtually meaningless. I have a MacBook Pro with almost 1000 charge cycles and it’s got ~93% battery health after 8 years. Lithium batteries are happiest around 40% state of charge. The closer you can keep them to that magic number the longer they’ll last. But leave them fully charged, or even worse, fully dead and that’s the quickest way to kill them with “normal” use.

That's very impressive! My Macs are usually down in the 80-85% range after 500 cycles. Do you use any tools to limit charge state other than "optimized battery charging"?

Re: The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

#169

Post by stealer0517 »

soultrees wrote: post #54

I have an 11 pro as my main workhorse. Multiple years old, constantly running the battery to 2 % then charging to 100 and it still lasts all day for me. I feel like the concern I see going on in this thread might be a bit misguided.

[dead]

Re: The iOS option to charge battery to "80% Limit" shouldn't just be for iPhone 15

#170

Post by TheMiddleMan »

pnpnp wrote: post #77
TheMiddleMan wrote: post #25

Related: for MacOS, AlDente allows you to set a battery charge limit. https://apphousekitchen.com/ I've been using it successfully for around a year. It works pretty well sans a couple quirks due to hardware limitations e.g. if you plug in with the screen closed (sleep mode) it will charge fully to 100%.

Same. I have mine set to sit at ~50% while plugged in & still have 100% of my battery health. It’s an M1 Pro MacBook that I’ve had since launch.

I've also been using it on a 14" M1 MacBook since launch (Oct 2021). I'm currently at 86% battery health.

I keep it at ~80% limit normally with occasional charges to 100% for long trips, etc. I do spend a lot of time on battery though so it's charging and draining a lot, but rarely goes above 80% charge.

Thanks for posting your results, I'm curious just how much the charge limit helps battery longevity.

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