Apple changes default MacBook charging behavior to improve battery health • Hacker News Board

Re: Apple changes default MacBook charging behavior to improve battery health

#21

Post by leetcrew » Thu, Apr 16, 2020, 8:05 PM UTC

intopieces wrote: post #15

leetcrew wrote: post #11

Earlier quoted context omitted.

the optimal charge state for long-term storage of a lipo cell is about 33%. 50% is a nice buffer on top of that if you use it unplugged for an hour or so, then put it away.

The use case here is plugged in and, presumably, using the laptop, not storing. Is 50% still the ideal charge state, in that case?

maybe not, but it's probably not much worse than the optimal charge state. you want to keep a lipo cell at 3.7v for optimal longevity. usually this corresponds to above 20% charge but below 80%, but the concept of "charge level" is sort of arbitrary. the manufacturer has already set safety buffers on either end of the spectrum, but the exact amount will vary based on risk tolerance, application, etc.

Re: Apple changes default MacBook charging behavior to improve battery health

#22

Post by arprocter » Thu, Apr 16, 2020, 8:06 PM UTC

overcast wrote: post #4

rootusrootus wrote: post #3

I wish they'd give us the option (on the iPhone and iPad as well) to arbitrarily set the maximum charge level. Just like on my Tesla, I'd like to be able to tell my phone not to charge above 80%.

Then 500M people complaining on Reddit that their phones only charge to 80% for some reason.

They could probably get away with changing what is technically 95% to read as '100'

I realised the other day that Macs don't give 'battery time remaining' anymore, although I'm not sure when that was removed

Edit: apparently you can still see time remaining in Activity Monitor

Re: Apple changes default MacBook charging behavior to improve battery health

#23

Post by ben_w » Thu, Apr 16, 2020, 8:07 PM UTC

Huh. That explains why my MacBook Air is doing so much worse than I expected from the number of cycles it’s reporting.

It’s a mid-2013, so I’m not expecting much, but a few times I’ve seen “100%” when waking it unplugged, only for this to be immediately followed by an emergency shutdown, and when the reboot completes it claims “42%”.

It’s plugged in almost continuously these days.

Re: Apple changes default MacBook charging behavior to improve battery health

#24

Post by ashtonkem » Thu, Apr 16, 2020, 8:11 PM UTC

simonh wrote: post #10

6gvONxR4sf7o wrote: post #7

PSA: If you have a thinkpad, the lenovo settings app lets you control this too. In lenovo vantage, go to Device > My Device Settings > Battery settings > Battery Charge Threshold.

Except that's a fixed threshold you have to set manually. This tracks the thermal and charging profile of the battery, learns it's characteristics and adjusts the threshold dynamically.

Which has a huge impact on battery health. Good and bad battery management explains a non trivial difference between high and low quality LiPo battery products.

Re: Apple changes default MacBook charging behavior to improve battery health

#25

Post by idoby » Thu, Apr 16, 2020, 8:12 PM UTC

They should just make 50% the new 100% and then let you "supercharge" to 150% when you need to. I'm kind of surprised Apple hasn't done this already.

Re: Apple changes default MacBook charging behavior to improve battery health

#26

Post by floatingatoll » Thu, Apr 16, 2020, 8:14 PM UTC

ben_w wrote: post #23

Huh. That explains why my MacBook Air is doing so much worse than I expected from the number of cycles it’s reporting. It’s a mid-2013, so I’m not expecting much, but a few times I’ve seen “100%” when waking it unplugged, only for this to be immediately followed by an emergency shutdown, and when the reboot completes it claims “42%”. It’s plugged in almost continuously these days.

What you describe does sound just like a battery that was almost always fully charged, and is about .. six? years old. You may want to try the “rumored to work” calibration process, or replace the battery after the latest OS update:

https://help.ifixit.com/article/265-battery-calibration

Which is essentially “set it never to sleep automatically, plug it in overnight, unplug it for 24 hours lid open and let it die and stay dead a while, charge it fully” without ever interrupting the charging process.

On a healthy battery this will slightly reduce capacity each time due to deep cycle so don’t go doing this if you’re not experiencing “shuts down at 42%“ problems!

Re: Apple changes default MacBook charging behavior to improve battery health

#27

Post by jonfw » Thu, Apr 16, 2020, 8:14 PM UTC

sahaskatta wrote: post #16

6gvONxR4sf7o wrote: post #7

PSA: If you have a thinkpad, the lenovo settings app lets you control this too. In lenovo vantage, go to Device > My Device Settings > Battery settings > Battery Charge Threshold.

The Dell XPS 13 also offers an interface in the BIOS that lets you set a charge limit, hours not to charge the laptop, and a bunch of other great controls. The only big issue is that they don't expose it through a friendly UI within Windows 10. It's nonsense that I need to go to the BIOS to tweak these settings.

What's really nice about that approach is that I run linux on mine and it all still works perfectly!

Re: Apple changes default MacBook charging behavior to improve battery health

#28

Post by geoelectric » Thu, Apr 16, 2020, 8:16 PM UTC

ben_w wrote: post #23

Huh. That explains why my MacBook Air is doing so much worse than I expected from the number of cycles it’s reporting. It’s a mid-2013, so I’m not expecting much, but a few times I’ve seen “100%” when waking it unplugged, only for this to be immediately followed by an emergency shutdown, and when the reboot completes it claims “42%”. It’s plugged in almost continuously these days.

If you check the power tab under System Information, you can find some battery health info that might be illuminating. For example, my newish MBP16:

  Charge Information:
  Charge Remaining (mAh): 8362
  Fully Charged: Yes
  Charging: No
  Full Charge Capacity (mAh): 8647
  Health Information:
  Cycle Count: 18
  Condition: Normal

Looking it up, specced full capacity is 8818 mAh, so I'm at 98% health right now--probably lost a point or two because I leave it constantly plugged in at work. Willing to bet yours is much lower.

There are a few apps out there that can do a better analysis too. CoconutBattery used to be a good one, no idea if it's still around, but they were common.

Re: Apple changes default MacBook charging behavior to improve battery health

#29

Post by bochoh » Thu, Apr 16, 2020, 8:17 PM UTC

rootusrootus wrote: post #3

I wish they'd give us the option (on the iPhone and iPad as well) to arbitrarily set the maximum charge level. Just like on my Tesla, I'd like to be able to tell my phone not to charge above 80%.

The only thing wrong with my Note 8 at this point is battery life. I'd gladly have dealt with 80% charge over its entire life in order to still have a good battery life now.

Re: Apple changes default MacBook charging behavior to improve battery health

#30

Post by jb775 » Thu, Apr 16, 2020, 8:18 PM UTC

>Charging a modern laptop battery to 100% and leaving it there for extended periods of time—especially at warm temperatures—can dramatically reduce the battery’s usable life.

This has been known for years, and this feature is relatively simple to build. I don't think it's an act of benevolence from Apple, I think the estimated cost of another class-action lawsuit has surpassed the estimated gain from decreasing the perceived life of MacBooks.