What should I limit my battery charge level to?

[teidon]

I've been fast charging the crap out of my 11 Max since new and it's still 100%. It has been charged repeatedly with Apple's 30 watt USB C adapter at home and Anker's 30 watt USB C charger in the car.
I don't think speed hurts anywhere as much as charge % and temperature.

If it was, Tesla wouldn't be using their supercharging network as they would get slammed with warranty claims.

A bit of googling tells that the 30W charger charges iPhone 11 from 0% to 100% in little over 2hours. This is about 1C charge rate and safe for all types of Li-Ions. iPhone 11 can apparently be charged at 22W at max, so having faster charger than that doesn't have any benefits (but doesn't hurt either).

Tesla's battery is probably limited between 30% and 80% charge like most EVs. That range charges pretty fast, so unless there is a charger that charges it from "empty" to "full" in less than 45mins, the charging rate would be 1C or less. For example the home chargers for Tesla can apparently charge them to full in 12 hours, which would be less than 0.1C charging rate. The recommended charging rate for Energy Cell type Li-Ions is 0.5C to 0.8C.

But in most cases the chargers don't charge Li-Ions too fast. The problem is those super fast chargers (like Qualcomm Quick Charge). If the batteries in those systems aren't designed to handled that fast charging, it's harmful to the battery.

I just thought of another thing That may have helped contribute to my previous computer (fan-less MacBook) having a degraded battery condition:

When I left it to go to lunch (or exercise, or whatever) I left it running. Worst of all was that I had a screen saver set up to the run which took lots of CPU power). My laptop was always quite warm when I got back (thus, not good for the battery)!

I actually noticed that too. The fancy animated screensavers generate a lot of heat and my MacBook Pro 16"'s fans kicks in after like 10 or 20 mins when those screensavers are on. Because of that I stopped using them and use instead the one that has black background with user defined message.

 

[magbarn]

A bit of googling tells that the 30W charger charges iPhone 11 from 0% to 100% in little over 2hours. This is about 1C charge rate and safe for all types of Li-Ions. iPhone 11 can apparently be charged at 22W at max, so having faster charger than that doesn't have any benefits (but doesn't hurt either).

Tesla's battery is probably limited between 30% and 80% charge like most EVs. That range charges pretty fast, so unless there is a charger that charges it from "empty" to "full" in less than 45mins, the charging rate would be 1C or less. For example the home chargers for Tesla can apparently charge them to full in 12 hours, which would be less than 0.1C charging rate. The recommended charging rate for Energy Cell type Li-Ions is 0.5C to 0.8C.

But in most cases the chargers don't charge Li-Ions too fast. The problem is those super fast chargers (like Qualcomm Quick Charge). If the batteries in those systems aren't designed to handled that fast charging, it's harmful to the battery.


I actually noticed that too. The fancy animated screensavers generate a lot of heat and my MacBook Pro 16"'s fans kicks in after like 10 or 20 mins when those screensavers are on. Because of that I stopped using them and use instead the one that has black background with user defined message.

The C rating of lipos doesn't necessarily mean 1C=1Hour charge
Lipo Charge/Discharge rate=Lipo Capacity x C Rating

It's not an "effective charge rate" based on time, it's basically how just much current (amp rate per hour so this is where time is only factored directly) vs. the total capacity of the battery.

A Tesla supercharger will charge a Long Range Model 3's 75Kwh battery pack at 150 Kwh when at the 20-80% charge level, but once over 80% it rapidly drops off from there
So at optimal charge capacity, Tesla chargers their Model 3 at 2c

My 11 Pro Max has a ~15Wh battery, during it's charging peak roughly between 5-50% Apple will fast charge at ~22Wh into the battery until it hits a little over 50% capacity then rapidly lowers the charge rate. So the iPhone 11 Pro Max will peak at ~1.46c

The 11 Pro is even faster with its 11.67wh battery as it charges around 20 watts max so around 1.7c at max charge rate

Invio labs did some serious testing on the 11 Pro

It's charging peak rate for about the 1st half of the charge and by the time it get's to 80+%, it's already down to 7 watts or 0.6c

If we based it on how you're calculating c, it would appear it's a 0.5c charge rate as it's taking 2 hours to charge, but that isn't true as the battery is being charge at 1.7c maximal rate and tapers off from there.

 

[yukari]

...

I actually noticed that too. The fancy animated screensavers generate a lot of heat and my MacBook Pro 16"'s fans kicks in after like 10 or 20 mins when those screensavers are on. Because of that I stopped using them and use instead the one that has black background with user defined message.

I've stopped using screensavers in favor of having the display turnoff after 10 min.

 

[coffeeplease]

I've been using it for a month or so and have not had any problems. You can monitor using coconut battery or even using System Info on the mac. Does not seem to cause any problems.

I have been keeping mine between 50-60% (typically at 55%) when plugged in. Only when I know I will be traveling or away from a power source I would charge it to 80%. I have not charged to 100% since. I will charge it to 100% if I know I will be using the computer away from a power source for more than 5 hours. But these days, there is a power source nearby no matter where you so.

Since you have been using it for a month, how has your battery capacity changed, if at all?

 

[BigMcGuire]

My observations of using Charge Limiter - while I see no difference in battery temperatures (monitoring via coconutBattery) --- it seems the armrests are a lot warmer than I remember them being. But could just be me. I'm still using it. I have it set to 75% now because I'm using my laptop ... on my lap, a bit more than usual. Working all day at my desk = I don't wanna sit at my desk for the rest of the day.

In the past I've seen value in keeping my battery 90-100 because the charging is slow (trickle charging). So I think I might set the charge limiter to 85% - that may keep the armrests cool? Something I'm going to try soon.

Haven't noticed much of a difference between 60% and 75%. Will be upping it to 85% soon.

 

[yukari]

Since you have been using it for a month, how has your battery capacity changed, if at all?

Funny you mentioned it. It actually increased significantly.

As you can see, since I've started using Charge Limiter, my MBP's battery capacity went from about 7400 to 7570.

My previous battery got swollen and had it replaced under AppleCare+. Whenever I work at home or at the office, it is plugged in all the time. After I got my battery replaced, I started using Charge Limiter (I have OS 10.14.6 - Mojave), I've kept my charge at 50-55%.

 

[BigMcGuire]

Funny you mentioned it. It actually increased significantly.
View attachment 930634

As you can see, since I've started using Charge Limiter, my MBP's battery capacity went from about 7400 to 7570.

My previous battery got swollen and had it replaced under AppleCare+. Whenever I work at home or at the office, it is plugged in all the time. After I got my battery replaced, I started using Charge Limiter (I have OS 10.14.6 - Mojave), I've kept my charge at 50-55%.

That is amazing!

My health has gone up 3% since 10.15.5 came out and I started using Charge Limiter. Wish I had found out about this earlier. 93% to 95.1% and growing.

Your post... has me convinced maybe I won't do 85% charge limiter but ... 55%. ....

 

[yukari]

I keep mine at 50% sometimes at 55% depending on how I feel that day. No rhyme or reason whatsoever.

When I travel, I charge it to 80% unless I know I will be using the computer away from a power source for more than 5-8 hours.

I strongly recommend not to charge more than 80% unless absolutely needed.

 

[iRun26.2]

What kind of temperature reading are you guys seeing on your batteries when the system is under heavy load (fans on)?

Are the two temperatures the same (battery #1 and battery #2)? One of mine is always 4C higher than the other.

 

[BigMcGuire]

What kind of temperature reading are you guys seeing on your batteries when the system is under heavy load (fans on)?

Are the two temperatures the same (battery #1 and battery #2)? One of mine is always 4C higher than the other.

Clamshell mode = 101-105F. (38.33C - 40.55C)
Laptop mode = 95-100F. (35C - 37.77C).

Idle I see low 90F clamshell and mid 80F for laptop mode.
(Above records are coconutBattery only).


Right now doing Macrumors:

Above screenshot is from iStat Menus. I usually only watch coconutBattery.

Looks like coconutBattery pulls from TS2.

 

[iRun26.2]

Clamshell mode = 101-105F. (38.33C - 40.55C)
Laptop mode = 95-100F. (35C - 37.77C).

Idle I see low 90F clamshell and mid 80F for laptop mode.
(Above records are coconutBattery only).


Right now doing Macrumors:
View attachment 930667

Above screenshot is from iStat Menus. I usually only watch coconutBattery.

Looks like coconutBattery pulls from TS2.

That is pretty much what I see although mine is a little higher in "Laptop mode" (I've seen a 41C on Battery #2). I started a thread asking what other people were seeing but I didn't get hardly anyone responding. I'm relieved that you see a 4C difference in temperatures too. I thought that might be a sign of something wrong with mine.

 

[coffeeplease]

Funny you mentioned it. It actually increased significantly.
View attachment 930634

As you can see, since I've started using Charge Limiter, my MBP's battery capacity went from about 7400 to 7570.

My previous battery got swollen and had it replaced under AppleCare+. Whenever I work at home or at the office, it is plugged in all the time. After I got my battery replaced, I started using Charge Limiter (I have OS 10.14.6 - Mojave), I've kept my charge at 50-55%.

I've been capping it at 75%, but still seeing the battery capacity drop a bit (although it only has been a few days and could just be fluctuations). I think I'll just cap it at 50-55% now, although it's a little more inconvenient to change it back and forth when I need to use it off charger. Thanks for showing your battery history, really insightful.

That is amazing!

My health has gone up 3% since 10.15.5 came out and I started using Charge Limiter. Wish I had found out about this earlier. 93% to 95.1% and growing.

Your post... has me convinced maybe I won't do 85% charge limiter but ... 55%. ....


View attachment 930640

Based off your previous post, you capped it at somewhere between 60-75% from June 12 until now? It's weird it went down to 90% then spiked back to 95%, unless you changed something around that day. It does suggest that 75% would also be fine to set as the cap.

 

[macagain]

This thread has caused me to learn a lot more about Li-ion batteries!

Based on this thread, I've started using AlDente (thanks David Wernhart) to limit the max charge to 55% when I'm not traveling (i.e. now and for who knows how long ), and probably 95% when traveling. I know various folks recommend unplugging at night, but it seems to me that that's not necessary since the max charge is limited (esp. to a low # like 55%). The whole unplugging kinda makes sense to keep the battery getting into an "overcharged" state, but if it's limited to 55%, will it ever be so? Thoughts?

On another note... about clam shell mode. On my old late 2013, for awhile I was using it in clam shell mode powering 2 4k monitors. I thought that that would ease the work load on the GPU a bit by eliminating one screen. However, the machine ran really really hot. I think the GPU location is above the kb, you can touch it and it's pretty toasty. The way the macbooks are designed, I think the whole top of the case provides a bit of heat sink function, and with the lid closed a lot more heat is trapped inside. With that theory, I stopped using clam shell mode, and sure enough temps dropped (prob 5-10 degs consistently if I remember). I have to believe that the extra heat also contributed to the battery eventually swelling. I truly believe that clam shell mode is to be be avoided, esp. if you're using multiple 4k/5k monitors. I definitely still stay away from it on my 2018 15" (which just got its swollen battery replaced). Sorry for the tangent, but I think it's one of the things that's detrimental for battery health.

 

[golfnut1982]

My .02. I have been reading this thread and others about this topic. I kept the battery health management ON when the feature became available. I have also been following Al Dente app's comments. Here is what I found. With BHM on, it worked. design capacity dropped as intended, cycles increased as intended preserving battery health according to Apple. Then I turned it off and waited to see what happens when I'm plugged in again. I was genuinely curious what will happen to my battery. Design capacity went back up to 100%, health went backs up to 100%. All pretty fast. So it seems in theory, if you are plugged in all the time like I have been since working from home, then it makes sense to enable it. Cycles will go up though.It seems the range goes from 100 to 90 back up to 100. I read every 18 hrs (not sure though). But if I was not using my MPB all day like I am now, and I was at work then using it for casual stuff when I got home, then I probably would just plug in when needed and unplug when not. My 2013 MBP still has 94% health and around 258 cycles.

I tried Al Dente too. It does work nicely. You can adjust the charge level at will and the charging stops and starts as required.

 

[magbarn]

My .02. I have been reading this thread and others about this topic. I kept the battery health management ON when the feature became available. I have also been following Al Dente app's comments. Here is what I found. With BHM on, it worked. design capacity dropped as intended, cycles increased as intended preserving battery health according to Apple. Then I turned it off and waited to see what happens when I'm plugged in again. I was genuinely curious what will happen to my battery. Design capacity went back up to 100%, health went backs up to 100%. All pretty fast. So it seems in theory, if you are plugged in all the time like I have been since working from home, then it makes sense to enable it. Cycles will go up though.It seems the range goes from 100 to 90 back up to 100. I read every 18 hrs (not sure though). But if I was not using my MPB all day like I am now, and I was at work then using it for casual stuff when I got home, then I probably would just plug in when needed and unplug when not. My 2013 MBP still has 94% health and around 258 cycles.

I tried Al Dente too. It does work nicely. You can adjust the charge level at will and the charging stops and starts as required.

I just use Al Dente now. I'd rather just lock it at 60% and not have the charge cycles go up

 

[golfnut1982]

Are you plugged in all the time? As far as cycles go, it's my understanding when the battery hits 100% when charging then it racks up another cycle correct ie going from 90 to 100 ten times is 1 cycle? Going just below it would not right? I'm hoping to clarify this for me and others.

 

[Supra Mac]

Problem being it cycles at the extreme end of charge, may help but not really. My response on this from another thread:

The whole battery health management is a bigger benefit to Apple and not the end user. Extends battery just enough to reduce battery warranty claims while not moving the needle much on extending battery life long term. To do that you need something like Al Dente and set the max level to 80% and switch manually higher if you please when needed.

When I had it enable (Apple feature) it just went from 100-90-100% once a day, just adding cycles at the extreme end of charge. My work laptop HP Elite "something or other" keeps my battery 75-80% with the Bios enable feature to extend battery life. So looks like other manufactures provide this to benefit the end user.

 

[magbarn]

Problem being it cycles at the extreme end of charge, may help but not really. My response on this from another thread:

The whole battery health management is a bigger benefit to Apple and not the end user. Extends battery just enough to reduce battery warranty claims while not moving the needle much on extending battery life long term. To do that you need something like Al Dente and set the max level to 80% and switch manually higher if you please when needed.

When I had it enable (Apple feature) it just went from 100-90-100% once a day, just adding cycles at the extreme end of charge. My work laptop HP Elite "something or other" keeps my battery 75-80% with the Bios enable feature to extend battery life. So looks like other manufactures provide this to benefit the end user.

+1

If Apple wanted to maximize battery life while making it as simple as possible for the costumer would be to set up a slider like this in the battery preference tab

Max battery lifespan......................Balanced..................Maximum Battery Charge Capacity/shortest lifespan
.........O-----------------------------------O--------------------------------------0
20-80% charge.............................15-90%......................................0-100%

 

[mcaswell]

If Apple wanted to maximize battery life while making it as simple as possible for the costumer would be to set up a slider like this in the battery preference tab

Agreed. I still don't fully understand how Catalina's battery life management thing works, but if it's anything like the iPhone version, where it "learns from your daily charging routine", it's all but useless for me, as I don't have a daily routine... my MBP stays plugged in almost all of the time (only maybe once a month do I use it on battery). So, I just use Al Dente, and manually set it to 60%, as that will provide a decent amount of battery if I unexpectedly need it, and I can increase it if I know I'm going to be using it unplugged extensively the next day.

I think this is perfect, but if Apple wants to make it more Apple-like, a slider like you describe would be infinitely more useful than what exists in the OS now.

 

[yukari]

Are you plugged in all the time? As far as cycles go, it's my understanding when the battery hits 100% when charging then it racks up another cycle correct ie going from 90 to 100 ten times is 1 cycle? Going just below it would not right? I'm hoping to clarify this for me and others.

With regards to the charge cycle count, my empirical observation shows it is the amount of total discharge that counts. So even if you have it plugged in all the time, it discharges a little and recharges back to the set level (mine is between 50 and 55% using Charge Limiter - I still have Mojave). When the total discharge gets to a certain amount it will then increase the cycle count.

Without the actual code or hardware configuration book, this is just my observation. It also makes a most logical way of counting.

 

[sdedalus1]

Does anyone know if there are hardware limitations to the Charge Limiter script? I've tried it on a 2008 aluminum unibody Macbook running Sierra 10.12.6, which I use as a music server, but after entering a max charge value I get "There was an error setting the charge limit. Make sure you have administrator privileges." This is with the correct admin password.

Would love to get it to work: I'm on a year-old third party battery but because I've been running it plugged in almost all the time, it is already on "Replace Now" with just 14 cycles.

For the record, this model doesn't officially support Sierra, but I have installed it with DOSDude's macOS Sierra Patcher Tool for Unsupported Macs. Don't know if it's a hardware or software problem.

 

[BigMcGuire]

Are you plugged in all the time? As far as cycles go, it's my understanding when the battery hits 100% when charging then it racks up another cycle correct ie going from 90 to 100 ten times is 1 cycle? Going just below it would not right? I'm hoping to clarify this for me and others.

Batteries - Why Lithium-ion?

Learn why Apple rechargeable lithium-based technology provides the best performance for your iPhone, iPad, iPod, and MacBook.

www.apple.com

See the bottom of that page.

Partial charges add up to a full charge eventually, so yes, 90 to 100 ten times is 1 cycle. Yep.

 

[yukari]

That confirms what I said above.

 

[iRun26.2]

Funny you mentioned it. It actually increased significantly.
View attachment 930634

As you can see, since I've started using Charge Limiter, my MBP's battery capacity went from about 7400 to 7570.

My previous battery got swollen and had it replaced under AppleCare+. Whenever I work at home or at the office, it is plugged in all the time. After I got my battery replaced, I started using Charge Limiter (I have OS 10.14.6 - Mojave), I've kept my charge at 50-55%.

Is this a spreadsheet you created or did the computer log the information for you automatically?

Where is this information?

 

[coffeeplease]

Is this a spreadsheet you created or did the computer log the information for you automatically?

Where is this information?

This is coconutBattery, you can set it to run in the background and log battery capacity every day.
[automerge]1594172228[/automerge]

Agreed. I still don't fully understand how Catalina's battery life management thing works, but if it's anything like the iPhone version, where it "learns from your daily charging routine", it's all but useless for me, as I don't have a daily routine...

So battery health management is actually different from optimized battery charging that we see in iOS. Big Sur gives you both options, battery health management (the one also in Catalina) AND optimized battery charging (learns from your routine to wait at 80% before fully charging). For the former, we still have no clue what "peak capacity is reduced" does. Is it only reduced for the 90% drain, or is it reduced permanently while the option is on??

You can see both these options in this video around 25min mark: