What should I limit my battery charge level to?

JohnDoe12

macrumors member
Original poster
Nov 14, 2017
48
35
So I want to limit my battery charge on my MacBook Pro. Anyway, what should I limit it to? 80%? 70%? Or 50 or 40%? Apple suggests to store their battery at 50%, so maybe at that? I'm going to be running off of AC power, by the way.

Thanks!

___

DISCLAIMER:

Before some smartass decides to tell me that it won't help increase the longevity of my battery, I don't need your opinion. My motive is to keep the battery cycle count low to increase resale value when I sell it next year. I know a bunch of smartasses will try to tell me that there's no difference, but a fact you can't argue with is that a lower cycle count increases resale value.

Once again, if you want to be a smartass, please don't comment. I mean I'm not stopping you, but I'll pretty much just ignore you. So don't waste your time telling me how it won't help my battery health. I know, and I don't give a f. It's not the point of the discussion, keep your comment spam somewhere else.

___

Edit: It seems like, despite my disclaimer, people still want to tell me that what I'm doing is inconvenient for me. No, it's not. I set my battery max charge level to 50% and I forgot about it. I'm not worried about my battery health at all. I have peace of mind that my battery's going to last a bit longer since it's constantly at 50%, rather than 100%. This is not a routine I do every day, I literally just set it once a few weeks ago and forgot about it. And since my laptop is tethered all the time I've never needed to make full use of the battery. Keep this in mind before you comment.
 
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JohnDoe12

macrumors member
Original poster
Nov 14, 2017
48
35
I don't care what you do one way or the other, but I have to ask... why does limiting the *percentage* change the number of cycles, if you're running it off AC power?
My bad, should have clarified. Apple's health management thing drains and refills it between 90 and 100, and that eventually adds cycles. I could turn it off, but then it'd be around 100% for months, and I think it's better if I just leave it at say 50% for a few months.
 

BigMcGuire

Contributor
Jan 10, 2012
5,396
6,750
California
I assume you have software that will allow this? I don't know of a way to do this without 3rd party software. Apple's charging management is very efficient - yes, it'll keep the battery healthy by doing 95-100% now and then, but for the most part it just sits in a charged state and runs entirely off of the wall power.

My 2017 MBP 13' is 25 months old and I have 79 charge cycles because I leave it plugged in most of the time. Up until recently I was down to 94% of design capacity.

Now if I could, I'd set my MBP to 60-80% instead of having it at 95%.

I'm disappointed to see Mac OS's new battery longevity features just drain the battery to 80% then back to 100% now and then to keep the cells energized. I'd have much rather preferred a 50-80% setting and some "exercise" routines that happen once or twice a week.

Edit: That said, with Mac OS' latest update, my battery health has gone up 2-3% (and stayed there) thanks to the exercising. Health was at 94% now it is at 97.2%.
 

leman

macrumors G4
Oct 14, 2008
10,673
5,188
If your goal is to reduce the battery cycle count, you should limit the charge to whatever the lowest number is that your are still comfortable with.
 

Fishrrman

macrumors Core
Feb 20, 2009
19,390
6,699
Charge the battery to 100%.

If you normally leave the charger connected, take it OFF charge 3-4 times a week (at least) and let it run down to about 35% or so. Then reconnect it to the charger.

Each and every night, take it OFF the charger while the computer sleeps.
Better yet, SHUT IT DOWN at night and reboot in the morning. Doesn't take very long.
 
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Fishrrman

macrumors Core
Feb 20, 2009
19,390
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"Your suggestion may be good for battery health, but it’ll increase the cycle count."

Well, ok.
But isn't "the health" of the battery more important than "cycle counts"...?
Just askin'...
 
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ihakim

macrumors regular
Jun 11, 2012
142
62
Stanford, CA
"Your suggestion may be good for battery health, but it’ll increase the cycle count."

Well, ok.
But isn't "the health" of the battery more important than "cycle counts"...?
Just askin'...
Not to OP. He is trying his best to get $50 more resale value in the future while hindering his current use and enjoyment of his laptop. 😂
 
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CheesePuff

macrumors 6502a
Sep 3, 2008
745
499
Southwest Florida, USA
My bad, should have clarified. Apple's health management thing drains and refills it between 90 and 100, and that eventually adds cycles. I could turn it off, but then it'd be around 100% for months, and I think it's better if I just leave it at say 50% for a few months.
Thats now how it works, it simply runs off of AC power once its fully charged, and the battery naturally loses its charge over time, once it hits 94.9% it charges it back to 100% again. This is perfectly normal and does not stress your battery. I have a 2015 MBP 15" that I have left on the charger for 95% of its life, and its battery capacity is still at 98% years later.
 

posguy99

macrumors 65816
Nov 3, 2004
1,163
671
Thats now how it works, it simply runs off of AC power once its fully charged, and the battery naturally loses its charge
Hasn't been that way for a long time, this is why, for example, an MBP will LOSE battery charge if heavily loaded, even if plugged into AC. The laptop always runs off the battery.
 

jerryk

macrumors 603
Nov 3, 2011
5,800
2,908
SF Bay Area
I assume you have software that will allow this? I don't know of a way to do this without 3rd party software. Apple's charging management is very efficient - yes, it'll keep the battery healthy by doing 95-100% now and then, but for the most part it just sits in a charged state and runs entirely off of the wall power.

My 2017 MBP 13' is 25 months old and I have 79 charge cycles because I leave it plugged in most of the time. Up until recently I was down to 94% of design capacity.

Now if I could, I'd set my MBP to 60-80% instead of having it at 95%.

I'm disappointed to see Mac OS's new battery longevity features just drain the battery to 80% then back to 100% now and then to keep the cells energized. I'd have much rather preferred a 50-80% setting and some "exercise" routines that happen once or twice a week.

Edit: That said, with Mac OS' latest update, my battery health has gone up 2-3% (and stayed there) thanks to the exercising. Health was at 94% now it is at 97.2%.
Proof exercise is not only good for us, it is also good for batteries.
 

hobowankenobi

macrumors 65816
Aug 27, 2015
1,313
395
on the land line mr. smith.
Interesting piece of software, from what I understand lithium ion batteries degrade the most when charging as this is when the most heat is generated. Ideally if you can keep the battery around 15C-20C it will greatly prolong its usable life.
I'm not sure this is correct. I see alot of info about increasing battery longevity having to do with not charing to 100%.

Not a temp issue.

Telsa, for example, using similar Li-Ion chemistry, default to about 90% to maximize battery life. You can charge to 100% if you want, but they recommend NOT doing that daily; only when needed for long trips. Clearly, charging to 100% is to be avoided in order to maximzie battery life.
 

jgorman

macrumors regular
Jul 16, 2019
182
99
Apple gives an estimate for the number of cycles, but your own use of the battery determines the actual number of cycles your battery will have. The reason they cite a 50% charge level as good is this puts the least strain on the battery by having half the lithium ions in the lithium cobalt oxide layer and the other half in the graphite layer.

Practically, keeping a 50% charge is really difficult, so often people recommend a range of 20-80% charge. The further you go in either extreme, the more stress on the battery and the fewer cycles it will have before degrading; all other things being equal.
 
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JohnDoe12

macrumors member
Original poster
Nov 14, 2017
48
35
Not to OP. He is trying his best to get $50 more resale value in the future while hindering his current use and enjoyment of his laptop. 😂
This is the exact "smartass" comment that I was asking people not to make. I'm not hindering my current use in any way, since my laptop is plugged into AC the whole time.

Also didn't realize you understood my personal situation better than me.

Go troll on another thread, please.

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Then your battery won't accumulate cycles anyway. Thus, no need for any special treatment.
Apple's battery health management feature increases the cycle count, even if you're on AC 100% of the time.
- - Post merged: - -

I'm not sure this is correct. I see alot of info about increasing battery longevity having to do with not charing to 100%.

Not a temp issue.

Telsa, for example, using similar Li-Ion chemistry, default to about 90% to maximize battery life. You can charge to 100% if you want, but they recommend NOT doing that daily; only when needed for long trips. Clearly, charging to 100% is to be avoided in order to maximzie battery life.
Yes, this is accurate. I believe Teslas recommend not charging to over 60% for general, everyday use—to improve battery life.

My situation is a bit different. I'm asking what to limit the battery charge to.
- - Post merged: - -

Apple gives an estimate for the number of cycles, but your own use of the battery determines the actual number of cycles your battery will have. The reason they cite a 50% charge level as good is this puts the least strain on the battery by having half the lithium ions in the lithium cobalt oxide layer and the other half in the graphite layer.

Practically, keeping a 50% charge is really difficult, so often people recommend a range of 20-80% charge. The further you go in either extreme, the more stress on the battery and the fewer cycles it will have before degrading; all other things being equal.
Okay... did you read my comment up there? I wrote about Charge Limiter, which keeps your battery level at 50%.

This "keeping a 50% charge level is difficult" is now a myth and needs to die.
- - Post merged: - -

Thats now how it works, it simply runs off of AC power once its fully charged, and the battery naturally loses its charge over time, once it hits 94.9% it charges it back to 100% again. This is perfectly normal and does not stress your battery. I have a 2015 MBP 15" that I have left on the charger for 95% of its life, and its battery capacity is still at 98% years later.
That's true, but having Apple's battery health management feature on runs through cycles. Guess I should have clarified that.
 
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jgorman

macrumors regular
Jul 16, 2019
182
99
This is the exact "smartass" comment that I was asking people not to make. I'm not hindering my current use in any way, since my laptop is plugged into AC the whole time.

Also didn't realize you understood my personal situation better than me.

Go troll on another thread, please.

- - Post merged: - -



Apple's battery health management feature increases the cycle count, even if you're on AC 100% of the time.
- - Post merged: - -



Yes, this is accurate. I believe Teslas recommend not charging to over 60% for general, everyday use—to improve battery life.

My situation is a bit different. I'm asking what to limit the battery charge to.
- - Post merged: - -



Okay... did you read my comment up there? I wrote about Charge Limiter, which keeps your battery level at 50%.

This "keeping a 50% charge level is difficult" is now a myth and needs to die.
- - Post merged: - -



That's true, but having Apple's battery health management feature on runs through cycles. Guess I should have clarified that.
I use Charge Limiter. I set it to 80%.
 
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BigMcGuire

Contributor
Jan 10, 2012
5,396
6,750
California
I'm a little leery running code that isn't signed - but - does it actually put the battery in a "not charging" state and run off of AC power?
 

jgorman

macrumors regular
Jul 16, 2019
182
99
I'm a little leery running code that isn't signed - but - does it actually put the battery in a "not charging" state and run off of AC power?
Well, when it is plugged in and the battery is at 80% (the limit I set), the battery's menu says "Battery is Not Charging," and the line below that says "Power Source: Power Adapter."

In reality, it is trickle charging, since the battery stays at 80% charge.
 
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