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Ask HN: Should I unplug my laptop charger at 100%?

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201–210 of 249 posts

Re: Ask HN: Should I unplug my laptop charger at 100%?

#201

If unplugging your charger at 100% and letting your battery run to 84% or whatever, and then plugging it back is so good for it, why doesn't Apple (or any other laptop manufacturer) just have the power controller do that automatically when your laptop is plugged in? I call malarkey on all of it. I've had my laptop plugged in for years and it sits at 100% most of the time. I don't have time to deal with that kind of h…

Many do. I've had several Windows laptops that want to do this.

Re: Ask HN: Should I unplug my laptop charger at 100%?

#202

Earlier quoted context omitted.

Yosemite is a total mess, but it has gotten slightly better with 10.10.3 (if you are willing to ignore the Photos app, which launches constantly for no reason). If you are willing to mess with drivers, you may want to try installing Linux. On a 2013 Air, battery life and performance (even graphics!) are surprisingly better with Debian Jessie than with OS X. Of course, it is a newer model than yours, but the drivers w…

My Photos app was launching because it got reset at the default action when my iPhone connected. It's possible that's what is happening to you too.

My iPhone and a couple flash drives do this, probably because it thinks my scanner is a camera. Unfortunately I can't stop it from launching (assuming I can disable it in Preferences) until it will actually launch—I have left it beachballing for a very long time and it still has not finished launching, so I just force quit it.

Re: Ask HN: Should I unplug my laptop charger at 100%?

#203
post #58

Source: I have a master's degree in mechanical engineering in hybrid vehicle powertrains, and a big part of my research was battery technology. I spent some time working with the folks at National Semiconductor learning this, so I have several primary sources. Disclaimer: my knowledge of the field is from ca 2010. 1) Lots of deep discharge cycles do negatively affect battery life. Try not to jump between 0% and 100%…

Having read similar perspectives I was always annoyed that there was no way to essentially pause the charging and perhaps run via trickle charge at a set percentage, so if I'm tethered to a desk for a week I could keep the battery at 70% and then choose to bring it to 100% if I expect a long day away from an outlet. Perhaps this is not plausible for some reason? Would it be control required at the battery firmware level? (Referring to an Apple laptop for example)

Re: Ask HN: Should I unplug my laptop charger at 100%?

#204
post #131
post #8

As I sit and look at the replies already coming in, may I just add an enormous [citation needed] to the entire discussion? A question brought on by too many conflicting anecdotes can not be resolved by throwing another unsourced anecdote on the pile. (Incidentally, I'm at least a bit curious myself as to the answer, and have my own pile of conflicting anecdotes I've read.)

If I were running a social network like this, I'd post questions with definitive answers like this one, see who voted up / wrote the wrong answers, and then block those people from voting / commenting again for a long time period. Do that enough times, and you'd quickly have the smartest site on the Internet. This thread literally has people posting links to Yahoo Answers.

Well, after you divide the total IQ to the zero remaining posters, you can choose what value you want for the mean.

Re: Ask HN: Should I unplug my laptop charger at 100%?

#205

Earlier quoted context omitted.

My Photos app was launching because it got reset at the default action when my iPhone connected. It's possible that's what is happening to you too.

My iPhone and a couple flash drives do this, probably because it thinks my scanner is a camera. Unfortunately I can't stop it from launching (assuming I can disable it in Preferences) until it will actually launch—I have left it beachballing for a very long time and it still has not finished launching, so I just force quit it.

Open the Image Capture application, and you can change the setting at the bottom-left of the window. It seems to get increasingly hidden with each OS release.

Re: Ask HN: Should I unplug my laptop charger at 100%?

#206

Earlier quoted context omitted.

This is my favorite technology superstition, some citation would help many people sleep easier it seems.

Statistics and citations today is the Bible quotes / racial stereotypes of yesteryear. Some modern-day pseudo-scientist poster will cite some study that says "80% of chargers waste power if left plugged in at 100% charge" will then draw the logically faulty conclusion that therefore you should unplug your charger. The fact that the statistic study necessary had to ignore extra variables like if you have a lot of stuf…

The perfect is the enemy of the good.

The question is simply "what do we know about this problem" not "what is the absolute unquestionable universal answer."

Also your comment has some interesting points but starting off by comparing statistics and citations to bible quotes and racial stereotypes isn't going to win you much support.

Re: Ask HN: Should I unplug my laptop charger at 100%?

#207

Earlier quoted context omitted.

That's nice to know. However, i'd rather buy a new battery after 5 years (if my laptop is still fit and the battery is dead), than having to complicate my life and think about when to unplug or charge my laptop multiple times each day for 5 years... My Macbook air from mid 2011 is currently at 100/6700*5629 = 84% battery health. (6700 = design capacity, gathered from "ioreg -l -n AppleSmartBattery -r".

Is your machine even operational? My macbook air from 2011 (with Yosemite) is sluggish to the point of being unbearable to use and just collects dust.

MacBook Pro (13-inch, Early 2011) 2.3Ghz i5, self-upgraded hardware to 16GB 1333MHz DDR3 RAM, Samsung SSD 120GB, caddy with 500GB HD, replaced battery with cheap Chinese, running 10.10.3 like a charm (only my SD-card slot never worked).

Re: Ask HN: Should I unplug my laptop charger at 100%?

#208
post #121
post #58

Source: I have a master's degree in mechanical engineering in hybrid vehicle powertrains, and a big part of my research was battery technology. I spent some time working with the folks at National Semiconductor learning this, so I have several primary sources. Disclaimer: my knowledge of the field is from ca 2010. 1) Lots of deep discharge cycles do negatively affect battery life. Try not to jump between 0% and 100%…

Why don't device manufacturers code this kind of thing into their power/battery drivers?

I'm not sure I'd want my battery to be "that" smart, safety measures coded into the power/battery drivers (which would be present on the battery itself, not main OS drivers) sounds about right. Optimizing and things like that I rather leave up to the OS, or even an APP (as long as it cannot do anything dangerous).

I mean it's one thing if my OS can control the charging cycle to some extend, whether Apple can install drivers (and bad guys bad stuff) on my Battery "smart" board.

It may seem like a big leap now, but I bet someday (or perhaps even now, why do people place tape on their webcams otherwise) it could become a problem.

But of course, to my knowledge so far Apple is doing a pretty good job in keeping Macs and OSX kind off secure (don't quote me on that), however than again I don't want OSX to become as restrictive as iOS or I'll have to switch to Linux t get my dev-tools working. (not a fan of that personally)

Re: Ask HN: Should I unplug my laptop charger at 100%?

#209

Earlier quoted context omitted.

That's nice to know. However, i'd rather buy a new battery after 5 years (if my laptop is still fit and the battery is dead), than having to complicate my life and think about when to unplug or charge my laptop multiple times each day for 5 years... My Macbook air from mid 2011 is currently at 100/6700*5629 = 84% battery health. (6700 = design capacity, gathered from "ioreg -l -n AppleSmartBattery -r".

Is your machine even operational? My macbook air from 2011 (with Yosemite) is sluggish to the point of being unbearable to use and just collects dust.

MBP 2009 here... works as good as new. Only upgrade was a SSD for the hdd. Still only 4GB RAM. Wouldn't want to do much video/graphics processing but everything else is fine.

Re: Ask HN: Should I unplug my laptop charger at 100%?

#210
post #185

Earlier quoted context omitted.

No. Leaving a battery at 100% is bad for the battery's life. Just as bad as deep cycling all the time. Even if your laptop is stationary, knock the charger out once a day and let it run on battery power for a bit.

Do you have a citation for that?

Check out Chester Simpson's work from Natl Semiconductor. I don't have a DOI available for you unfortunately, but Simpson is a great starting point.
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