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Battery Strategies
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ghporter
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Jan 10, 2021, 07:57 PM
 
Apple says you “need to keep the electrons moving” to maximize laptop battery life. Their suggestions don’t seem to be specific enough to address my usage patterns.

I’m thinking, from past experience, that if I leave my machine plugged in when I’m not using it, it will eventually reduce battery capacity - even with the latest generation of Lithium Ion battery.

I have thought that maybe I could connect the charger to a timer. Run it for some length of time that would provide plenty of charge, then turn off so the battery isn’t “always” being charged. This could be set for overnight hours when I’m never using the machine, and not get in the way at all.

Here’s the rub: I don’t have enough current technical knowledge about how either the laptop’s charging system works or how Lithium Ion batteries handle being charged for long periods of time.

While I’m asking this specifically about my 2015 MBP, the question really seems to apply to anything that has a non-user-replaceable battery.

So I’d appreciate anyone’s insight, experiences and helpful suggestions on this topic.

Glenn -----OTR/L, MOT, Tx
     
Spheric Harlot
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Jan 11, 2021, 12:36 PM
 
I use battery-powered devices mainly in order to have to worry as little as possible about when and where I use them.

I figure, if I spend all the machine’s life worrying about battery preservation, it might delay the inevitably necessary replacement by a few months. Over a lifespan of five or six years.

I’ve decided that it’s far more useful to just use my machines, rather than arrange myself around them any more than necessary.
     
Thorzdad
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Jan 11, 2021, 04:56 PM
 
My rule of thumb has always been: Do not use a set recharging schedule. Vary your recharging schedule as much as possible, i.e. Let the battery get down below 20% before you recharge, then next time recharge when it's only down to 40%. Just keep varying the percentages as much as possible. I've also heard that you shouldn't necessarily charge the battery to 100% each time either.
     
andi*pandi
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Jan 11, 2021, 09:55 PM
 
I feel like I've been told several conflicting things (don't charge until it's below x%... don't leave it charging all the time... let it fully drain...) so it is confusing knowing which is best.
     
Spheric Harlot
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Jan 12, 2021, 05:38 AM
 
Originally Posted by Thorzdad View Post
My rule of thumb has always been: Do not use a set recharging schedule. Vary your recharging schedule as much as possible, i.e. Let the battery get down below 20% before you recharge, then next time recharge when it's only down to 40%. Just keep varying the percentages as much as possible. I've also heard that you shouldn't necessarily charge the battery to 100% each time either.
Apple‘s optimised charging plan appears to disagree.
     
shifuimam
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May 6, 2021, 10:54 AM
 
sorry for the necro, just wanted to add:

* Never discharge a lithium ion or polymer battery completely. Doing so risks killing the battery completely and permanently.
* Use the battery from time to time. It seems Apple's batteries are particularly bad about crapping out if you leave them on a charger indefinitely. Other OEMs don't have this problem nearly as much. *shrug*
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subego
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May 8, 2021, 04:44 PM
 
Here are the general purpose lithium-ion “best practices” I got about 6 or 7 years ago.



It’s bad to let them get to zero.

It’s bad to keep them plugged in all the time.

So, let a battery get fully charged and then let it drain to 30%. Once it’s at 30%, charge it and then let it drain again.

That’s it.







Okay... there’s one exception.

With an alkaline battery, the voltage slowly drops as it gets used. The voltage tells you directly how full the battery is.

Lithium-ion batteries don’t work this way. The only time the voltage changes is when they’re totally full or are about to die. The voltage stays constant the rest of the time.

Unless the battery is totally full or almost empty, if the device is telling you how full it is, it’s just guessing. This is where the draining to zero comes in. The only reason to do it is if it’s guesses are way off. If they are, follow these steps to recalibrate them.

1) Fully charge the device
2) Unplug it, and let it drop to zero without plugging it back in
3) Plug it back in, and let it charge back to full without unplugging it

As per the best practices, this is bad for the battery, so it should be avoided if at all possible.
     
ghporter  (op)
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May 9, 2021, 10:03 AM
 
I had spent quite a lot of time where my MBP would be running off the charger or sleeping on the charger. And since I could only use it after work, it would be off the charger for an hour or two in the evening, then back on the charger (with the external drive connected for Time Machine) and sleep.

Way back in the day, there was a school of thought that basically called for putting your laptop charger on a timer. Only let it stay “plugged in” for a couple of hours at a time was thought to allow it to fully charge, but not “over charge” (if that was a thing), and otherwise let it be idle and “unplugged” - whether that idle time was actually off or sleeping/hibernating was never very clear.

With Apple’s ‘keep the electrons moving” advice, it still seems that running on the charger for extended periods is a bad idea. But it also seems that with these lithium batteries leaving the machine “sleeping” off the charger is bad because that sleep state isn’t exactly completely idle.

I haven’t let my MBP go all the way to zero in quite some time, so that’s on my list of stuff to do. That won’t change the fact that the machine says the battery needs replacement, but maybe getting into a workable habit that kills the battery as slowly as possible will help the replacement last longer.

Glenn -----OTR/L, MOT, Tx
     
Thorzdad
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May 9, 2021, 11:29 AM
 
My iPad Air won't run at all unless it's plugged-in to the charger. Without the charger connected, it drops from an indicated 100% to zero in about three minutes, tops, then dies.
     
shifuimam
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May 9, 2021, 03:52 PM
 
Batteries used to last longer.

I really dislike how disposable electronics have become - it's caused batteries to decline in overall quality.

I still have freaking PowerBook G3 batteries that work for around 30 minutes! Meanwhile my 15" MBP came out in 2012 and its battery is totally kaput. Lame.
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subego
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May 10, 2021, 10:36 AM
 
Originally Posted by ghporter View Post
With Apple’s ‘keep the electrons moving” advice, it still seems that running on the charger for extended periods is a bad idea. But it also seems that with these lithium batteries leaving the machine “sleeping” off the charger is bad because that sleep state isn’t exactly completely idle.
I’m confused. How would letting it sleep off the charger be bad?
     
ghporter  (op)
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May 10, 2021, 11:05 AM
 
I feel that there’s a lot going on in “sleep.” For example, it appears that Time Machine does its thing whether the machine is asleep or awake - though my impression may be incorrect, and I’d like to be educated if this is not the case. Maybe when I hook the machine up to its TM external drive it does the backup and then sleeps?

Otherwise, Apple’s relatively vague “keep the electrons moving” advice is pretty much “just use the thing.” Which doesn’t seem to take into account episodic use in a pattern like mine.

Glenn -----OTR/L, MOT, Tx
     
subego
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May 10, 2021, 11:15 AM
 
I apologize, but I’m still confused.

It’s sounds like you’re saying “Apple said I should use the thing, but sleep is bad because it’s still using the thing”.
     
shifuimam
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May 10, 2021, 11:31 AM
 
I'm guessing MacOS has something similar to connected standby in Windows - it's a feature of newer CPUs and chipsets which allows the computer to temporarily wake in a very low-power mode to do something (like push notifications for apps).

"Keep electrons moving" sounds like FUD to me. Lithium-based batteries are hypersensitive to overcharging and draining (i.e. totally draining so it can't start charging again), but like I mentioned earlier, this was far less of a problem in older generations of battery tech. It seems likely at this point that Apple cuts a lot of corners on their battery tech, so you have to baby the batteries to avoid permanently ruining the battery. The "best practices" they advertise are to keep their subpar batteries conditioned.

I used to have an IKEA cart set up as a laptop charging unit - at our last house, it was just Apple laptops ranging from a PowerBook 5300 to a 13" unibody MBP. Every laptop I had in there was still charging the installed battery. Even my Wallstreet II has a functioning lithium battery, in that the OS sees it, charges it, and it holds a (very small) charge. My Dell E6410, which sits on a charger all the time now, still has a functioning battery (again, it doesn't hold MUCH charge, but it functions) - and I used the hell out of the battery on that thing back when it was my main laptop. My modded clamshell's battery (I replaced it like...6 years ago?) finally bit the dust.

Electronics have become much more disposable as the years have gone by, and OEMs simply expect a device to only last 3-5 years, and plan accordingly. It's stupid.
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subego
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May 10, 2021, 11:59 AM
 
From what it sounds like, what Apple is suggesting is just the best practice for any lithium-ion battery.

Charge it up, let it drain to 30%, and then charge it up again.

The electrons are being kept moving during that period it’s draining. It doesn’t matter whether that’s from direct use, sleep, or the thing is off. It’s draining (electrons moving) under all these circumstances.
     
ghporter  (op)
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May 10, 2021, 04:51 PM
 
Yeah, it's my perception, not what Apple is saying, that's confusing you - and me. Some study of what Apple (and others) says about sleep has cleared up some of that for me.

Sleep is close to identical to what Windows calls "hibernation." The machine is all but fully off, and when it's triggered to come back on, it does so in close to exactly the same state as when it was caused to sleep. Where Windows actually changes the boot record to call up a special saved system image, then turns off, a Mac isn't completely off - at least not right away. Macs can sleep much quicker than PCs can hibernate because some of the state saving tasks are done after the interactive part of the OS has been shut down. So a Mac can do a TIme Machine update after it goes to sleep, but only right afterward.

I'm pretty much sure that the best option is to keep an eye on the charge level all the time. If it's high enough, don't charge it. If it's low, charge it fully, then unplug it. In between, the machine can be running, or off or sleeping, without making a difference in the overall strategy.

Glenn -----OTR/L, MOT, Tx
     
subego
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May 10, 2021, 05:31 PM
 
With my laptop, which I tend not to move around a lot (i.e., I’m using it next to a charger), I keep it plugged in when I’m using it, and let it drain otherwise. That’s not exactly the best practice, but close enough.

Unfortunately, right now my laptop is my main computer, so I’ve had it plugged in and on for a year. I’m sure the battery is a mess now. At least it hasn’t started to swell.
     
   
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