Unplug Your Laptop Now, or It Will Stay Plugged in Forever
gizmodo.comThe problem isn't plugging it in, the problem is naive control software and non-communicated expectations.
In contrast, at night I plug in my phone, and it "knows" I won't need it until the morning alarm goes off, so it avoids unnecessarily charging the battery too soon or too rapidly.
It's rather unfortunate that many laptops still do this to their batteries. The last time I bought one I made sure it has a smart charging feature: It charges the battery to a configurable upper level, then stops charging until the battery has dropped to another configurable lower level. Defaults are at 80% and 20%.
Also, the discharge takes a very, very long time when plugged in, as it feeds directly from the power supply.
Apple took this out of Mac OS somewhat recently. You can try to rely on their power management, but given battery decay is a common reason to buy a new machine I don’t trust them really.
If you have an Apple Silicon Mac I can recommend Battery [1]. It can keep your Mac at 80%, and even force discharge while plugged in to get there. It’s a CLI and status bar utility, I love it.
Alternative tool for macOS: "Al Dente" :
Thanks, that's exactly what I was missing. I don't know what heuristic Apple's magical 80% charging setting uses but it does absolutely nothing for me, all I wanted is a checkbox for a limit but that's not "smart" and unpredictable enough I guess.
Ooh, thanks for this. There's a similar plugin for Decky on Steam Deck too, in case any SD users are reading this.
...took what out of macOS? It definitely still does "smart charging", keeping it at 80% until just before when it has learned you are likely to unplug it.
If you have a highly irregular schedule, then sure, this may not be helpful. But I find that my and my wife's Apple Silicon laptops are usually kept at 80% unless we explicitly tell them to "charge to full now".
You can’t explicitly tell it to hold at 80% using system settings, when once you could. Glad it works for you and your wife.
Please explain like I'm five: if continuously charging and drawing power at 100% hurts my laptop's battery, why doesn't the laptop bypass the battery circuitry, keeping it idle, and use the incoming juice directly?
If you blow on this balloon, it'll inflate. If you inflate it a lot and then let it deflate it has all of these stretch marks. Those stretch marks are now a permanent defect.
The same happens with your battery. If you charge it to 100% a lot and leave it there then it gets "stretch marks" and the permanent defects affect how long the battery lasts.
So you'll buy a new computer in 2 years when the battery is dead.
I'm boycotting laptops until this gets fixed
I am on the same MB Air since early 2019 and short of very occasional travel in the last 5 years it stays plugged in all the time. Just got back from a trip where I had more than 5 hours of heavy usage on battery and went nearly 6 hours before I was looking for an outlet.
I’m not unhappy with that…so I am always a bit skeptical of these laptop plugged in all the time are bad claims because it just doesn’t match my recent experience.
Try finding a laptop that can limit maximum charge level in bios, eg lenovo or dell.
The issue is high voltage state and temp are bad for lithium ion batteries.
"In terms of longevity, the optimal charge voltage is 3.92V/cell"
https://batteryuniversity.com/article/bu-808-how-to-prolong-...
That maps out to roughly 65% charge state. So a little trickle charge on/off doesn't really help things much at all. You simply need to keep the battery in a lower charge state while plugged in for longer periods.
As bad as this is alone, the toxic combo that kills a plugged in laptop's battery in a year or two is regularly pushing it hard at full charge.
macOS actually does that somehow indeed. Not exactly, but it does prevent charge when it “guesses” the computer will stay plugged in for a long time based on previous usage.
Which isn't a solution, I just want a toggle so I know it works. I don't want to train some hidden logic so it correctly guesses what I want based on what someone on the other side of the planet assumed my usage pattern looks like.
> Which isn't a solution…
…for you. For me, I am perfectly content with the algorithm deciding, and then me, deciding when I know I am going to be disconnected outside of my normal usage pattern…telling the machine to charge it to a 100%.
Not builtin, but possible: https://apple.stackexchange.com/a/406961
ChromeOS too.
iOS too, most of android phones too, etc. And well, most of PCs too… https://support.microsoft.com/en-us/windows/use-smart-chargi...
Probably, most of the charge controller chips don't have that feature or it costs more to implement than the OEMs want.
It does, if the battery is 100% no more charging current goes in, so charging stops.
But the key point is that the battery will drop to 99% very quickly and on it's own because no battery can keep the energy in perfectly. So it's recharged for the missing 1% over and over again which causes the damage.
Unless some smart charging logic prevents that, see other comments here.
Edit: typo
It's not just this, it's literally bad to keep a lithium ion battery in a high voltage state, period. Simply taking a battery out and leaving it on the shelf in a high voltage state, otherwise unused, harms it.
Agree, not sure why though. Because the isolation degrades because of electrons breaking through it?
However, keeping "a lot" of energy in the battery is kind of the purpose, no one is using 50% max to increase battery life. But I guess most damage increases exponentially with energy stored, so charging it from 95% to 100% will damage it a lot more to than charging it from 90% to 95%.
The article's advice isn't the best. It's better to not cycle your battery whenever possible. Set your battery up to only charge when bellow a certain threshold (I do 70%) lower than the max charge (I have it set to 80%). This optimises for not over straining the battery (by not going to 100%) and it reducing cycles to a minimum for my everyday use only travelling between (desk) locations. I set this up through the power manager of KDE, without much effort. I expect this to be available to most Linux distributions and moderately modern laptops. I think I could also set this up on Mac OS when I was using that in the recent past (and I think it comes with something similar out of the box, but less conservative).
Your advice is good but your reasoning is misleading. Smaller more frequent charges are easier on a battery than less frequent larger charges of the same magnitude. Better to go from 70% to 80% five times than to go from 30% to 80% once. That's true with thermal control like most car batteries, and even more without thermal control, like laptops.
^this guy batteries.
but seriously, when they announced EV with lithium batteries, all I could think of was the baby sitting for batteries. Look at all the intelligence that goes into those EV car setups.
That's more annoying than the consequence, so I won't do it. I am not so poor and unskilled that a $79.99 macbook battery swap in a 10 years is worse than the daily annoyance of thinking about a plug every hour of my life. But that's all moot. The latest MacOS already accounts for this, and lets the battery drain while plugged in, instead of topping off to 100% https://support.apple.com/en-us/102338. So it's not even a real issue anymore.
> "The latest MacOS already accounts for this"
Does that actually work, though?
My iPhone does quite a terrible job at "optimized battery charging"...
It seems like laptops should treat 80% like its 100% and have a separate "overcharge" feature that can be activated manually or automatically on a schedule or when not on home WiFi.
My Toyota Prius does this with its NiMH traction battery. The battery is now 18 years old and only starting to show its age.
The article doesn't explain the why here... it's because 2 things impact lithium ion lifetime - voltage (both high and low) and temp.
"In terms of longevity, the optimal charge voltage is 3.92V/cell."
https://batteryuniversity.com/article/bu-808-how-to-prolong-...
That maps out to roughly 65% charge state.
There's a great app called AlDente for MacOS that allows you to set the charge limit while plugged in.
Is there a good reason why we can't tell our devices to charge the battery to say 70% and then internally disconnect the battery, so it's neither charging nor discharging?
Some laptop manufacturers include this mode. At least I have it in lenovos (not exatctly 70%, they allow cap at 80%), and have seen in some samsungs years ago.
Where do you set this? OS, BIOS or some Lenovo control software?
On Linux you can set this in /sys/class/power_supply/BAT?/charge_{stop,start}_threshold – you can read and write a percentage (1-100) to there. You'll have to set it on every boot.
I assume there's some way to do this in Windows as well, but I don't know it.
At least one of those; depends on the device. As sibling comments note, plenty of devices expose it in software, where in Windows you use the vendor's utility and Linux puts it in /sys, but I've got laptops that either don't do that or I couldn't find it but I could configure it in the BIOS settings. So you might have to dig around a little.
Lenovo vantage, under battery management or something like that. Has been an option for quite long.
ThinkPad has this. My battery only charges to 75% and it must drop to 50% before it starts charging again. You can configure any value for either setting with TLP.
On my thinkpad the screen dims after 30seconds without keyboard activity when not fully charged. Very annoying. It happens also when connected to a charger.
I regretfully set the bios to fully charge again to disable this auto-dim feature.
Is the screen dimming not a setting in your OS?
Dell laptops have had such a feature literally for a decade now
Yep. I'm using Linux on a XPS 13 and Dell provides Dell Command Configure, aka, cctk. I set mine to 65%.
https://www.dell.com/support/kbdoc/en-us/000178000/dell-comm...
That's good to know, I guess I'm curious why it's not (nearly) ubiquitous. Does it add significant cost and complexity to hardware design?
Dell has advanced power management options in the BIOS, I set it to keep the battery charged at 70%, which is ideal for lithium batteries. And you set a custom schedule on days you need the battery charged at 100% so that you can take the laptop with you at full capacity. It's not rocket science, and definitely something anybody reading this site should be able to figure out for their make/model. For MAC there is a similar app that resides in top system tray where you can also define max charge. (https://apphousekitchen.com/ )
A lot of this advice strikes me as folk theories. Just treat batteries as consumables and use the device as you see fit. Replace the battery as necessary every few years. There's no similar advice for avoiding doing an oil change for cars. Why treat laptop and phone batteries as if they're precious resources?
Somewhere down the line, many of us got the idea that our laptops should always be plugged in to improve their performance
Because the manfacturers made the firmware defaults downclock the CPU if it was on battery power.
Also, is it just me or does this article have an "AI generated" feel to it? The arguments it makes are somewhat in the "uncanny valley" between truth and fiction, and the phrasing of some of the sentences seems very unusual, especially this last one:
Stop charging your laptop past 100% today, so you can free yourself from being plugged in tomorrow.
Stuff like this also raises some red flags:
It’s when hen[sic] there are too many lithium ions on one side that the battery gets stressed.
Yeah, this does seem AI generated, or at least “AI assisted” in that it was primarily written by AI and a human slightly modified it and then stamped their name on it.
Just look at this paragraph:
“Many laptops sit on a charger throughout the workday and all through the night. We don’t even think about it; we just plug in everywhere. We’re charging at work, at home, at the coffee shop – a collective addiction to a laptop at 100% battery. There’s nothing more frustrating than a laptop that can’t hold a charge, but your charging addiction may be accelerating the issue.”
It’s entirely air. It says nothing. The transition to the “There’s nothing more frustrating than a laptop that can’t hold a charge” sentence also doesn’t make sense. It’s like an 11th grader padding their essay to 1000 words, except the entire article is like that.
But I feel like LLM wouldn't make such non-sensical content, unless they used some obscure LLM.
The article is over dramatized causing false statements, doesn't use any of the usual GPT4 lingo etc.
E.g. claiming that it is the "worst thing you could do".
Could be, yeah.
Personal anecdata:
- Work MPB which I got 2021-12, 99% of the time plugged in because I was WFH, last time I unplugged it to return it to my employer, the battery was at ~95% of max capacity (as reported by MacOS)
- Personal MBP bought 2021-12, only plugging in when battery was low, and 1.5y later the battery was at 80% of max capacity
It was then that I investigated a bit and learned the trick of charging only up to 80%, which is something that MacOS does automatically when it's constantly plugged in which preserves battery life.
Since then, my personal laptop also stays plugged in most of the time, its battery is almost always at 80% and the battery hasn't decayed further.
Another anecdote:
- 2012 MBP used by my parents, almost always plugged in. Battery died last year. Forgot the cycle count but it shocked me by how low it was. This was before they implemented the feature where it stops charging at 80%.
- 2015 MBP used by me, mostly plugged in for the first few years, then afterwards always on battery, at least one charge/discharge cycle every day (often more than one). Battery died 2 years ago (and was 3 years younger). Cycle count was something crazy like ~2000.
If your laptop is near power, plug it in.
I can confirm from my own experience that this happens.
First laptop at work, always plugged in (except for maybe one or two hours a week). After two years of use (maybe a couple more from a previous employee) the battery lasted 30 minutes.
Personal laptop. Mostly plugged in (except when traveling maybe 3-4 weeks per month) but with the charging at 80% capped (it's an option from the manufacturer). Almost 10 years later still holds around 1-2 hours (disclaimer: I don't use this laptop anymore except for occasional tests)
> Somewhere down the line, many of us got the idea that our laptops should always be plugged in to improve their performance.
Various things have different default behavior when not plugged in to the power (e.g. iTerm2 disables GPU rendering by default). This is just the one place I know that's a counterpoint (and there's a setting to disable that), but it's actually something that I've hit a few times while developing Ratatui.
Why not to implement a feature on all OSs that stops charging your battery once it gets at 100% and start the charging again at about 50%? It's healthy for the battery (aka it doesn't degrade it if it doesn't charge) and it's not letting you remain at 10% - from where it goes instantly at 0%. The dingus remains at how to make it happen, even if i've seen it getting into iOS and Android.
If you're running KDE, max charge can be set in advanced battery settings. Other Linuxes can set it at the command line.
Chargie solves this problem for smartphones: https://chargie.org
Next month, they will release a version for laptops: https://chargie.org/product/chargie-for-laptops-preorder
If you use your laptop as a laptop, the ideal charging habit is 100% and stop worrying about it. You paid for 100% of the battery, you want to use 100% of the battery. It doesn't make sense to artificially cripple the product to extend the life of the device for a questionable period.
Unless it's a desktop with ups, in which case it should stay at 50%-80%.
I do this with my phones. Notification pops up at 80% and I unplug it if I see it. If not oh well
Hard to tell if it max a difference but judging by battery health stats others are reporting I’d say yes.
Would be nice if device had a built in way to cap it for daily use and only go to 100% if travelling etc. I’m rarely away from a power socket day to day anyway
This is why modern laptops don't stay at 100% if the detect that they're always plugged in, no?
Yeah mine is always plugged in and stays at 60%. This article is stupid.
And one day you'll unplug it and complain "why is the battery at 80%? It was plugged in all day. Stupid manufacturer. I will tell everyone to avoid this piece of shit"
The least losing move for the manufacturer is to always charge 100%.
Or you can actually explain the feature to users and let them choose and users can learn.
On my Lenovo laptop I have a toggle I can switch any time between battery saver mode(stay at 80%) and fast charging mode (charge asap to 100%).
If when designing products you never even let users choose to learn, you guarantee you will have a stupid user base. Stop endorsing stupidity.
Note that this advice is wrong if you have a device with good software and settings. (aka maximum and minimum charge settings). Smaller more frequent charges are easier on a battery than less frequent larger charges of the same magnitude. Better to go from 70% to 80% five times than to go from 30% to 80% once. Especially on a laptop that doesn't have battery cooling.
Even worse, unplugging your laptop makes it use battery charge, adding additional wear to your battery.
Virtually all EV's have good software, so your electric car should be plugged into a charger as often as possible. It should be the same for laptops, unless you have one that is poorly configured; most are.
I usually shut down my computer when not in use. If the laptop remains plugged in even in its unpowered state, does the battery still degrade?
Yes. Per the article the problem is being at 100% charge.
My previous Intel MBP which I've used for every day charging to 100% and discharging to 20% or so has 600 cycles now, battery health is at 81% and has been hovering there. It's still fine, but my point is if you think of relying on applecare+ to replace your dead battery, they will only do so if it's under 80% reported health and my conspiracy is that there's some reported value stickiness around 80%, it will have to be really bad for it to go below, and without it going below no applecare+ replacement.
I disagree. 2022 mbp. Always plugged in... 5 charge cycles in total.
It seldom charges while plugged in. Even when down to 80% it alerts me it's not charging because I seldom use the battery.
Apple could change this behaviour silently and mess it up but for now it's perfect for my needs.
No one:
Gizmodo: "Somewhere down the line, many of us got the idea that our laptops should always be plugged in to improve their performance."
It’s worded a little weird there, but it’s not untrue. Laptops with high TDP CPUs and/or discrete GPUs will often perform significantly worse on battery, either by default or always.
It’s why whenever a new M-series chip launches, Apple makes sure to highlight how it performs every bit the same on battery as while charging.