Charging Laptop Battery to 80% Max When Plugged In All The Time?

My new dell xps 15 9520 uses windows 11 but this is just a general windows question so figure I post it here.


I have the laptop plugged into 2 external monitors and laptop is on almost all day. So when it is plugged in, it is 100%. I read somewhere a while back to make your laptop battery last longer, make it only charge up to 80%. Is this true or false? I heard that laptop batteries can actually figure things out so you charging it fully at 100% and continuing to use it like a desktop is similar to charging it max to 80%. Which is true?


How do i do this on my dell xps 15 9520? Do I need to download a dell application or there is something in windows 11 that does this? Also when you do it, you have to make sure your laptop is unplugged and make sure the battery goes to like 70% or so... then you start charging it then it will go max 80% only?


The one negative issue I have with this is if there is a power outage, then I would have 20% less battery than I do normally.


Do people who use their laptops as desktops and plugged in always do this or don't make any changes?


I like to add, that my old xps 15 9550 laptop, I believe I had to change the battery every 1.5 years or so. I believe 2 or 3 years is what is considered normal for battery replacement? The issue is my laptop is on almost all day. It is on probably 16 hours a day. I even had it on 24 hours for months and just lock it. So doing this would maybe increase my battery life for another 6 months? I know if you have your laptop on all day every day, battery will wear out faster than someone that has their laptop on say 3 hours a day etc.

I have an ASUS and an MSI laptop. In both cases there are manufacturer supplied apps that limit the charge to 80%. ASUS and MSI state that this improves battery life. I have implemented the manufacturers recommendations but the machines are not old enough to know if this works. There is hysteresis in the apps. Once the 80% is reached then charging stops and will not start again until the battery goes down to 70% even when the charger is powered.

So I read Dell Power Manager is the problem to allow to do this. But could I do this on windows 11 pro without downloading Dell Power Manager?


Can others confirm charging it to max 80% does extend the battery? Do you need to put a minimum percentage as well?


I intend to use this laptop as a desktop and plugged in with 2 external monitors almost always.


Also if you use a laptop while on battery, it does uses more battery when it is connected to 2 external monitors compared to just by itself right?


Would want opinion from dell xps users here.

How often do you change computers?
The average lifetime of a battery is up to 4 years, irregardless of charging level.

And external monitors do pull more power, but the actual amount depends on multiple factors, but again on average its not much.

I believe the 80% limit is to make us unplug the charger before we reduce battery life. There is nothing wrong to charge the battery at 100%, provided then you unplug it and let the battery discharge. If you keep the charger on at all times, even if battery is fully charged, eventually you will damage the battery and last only for 15-30 minutes. To make us keep an eye on the battery level and remove the charger they invented the 80% limit, so if we forget it and go past 80% but no more than 100%, then no harm done. If they would tell us to charge at 100% we would at some point forget the charger for too long and reduce battery duration. This is fine if we didn't blame the manufacturer for it. So to limit Warranty claims they set the limit to 80% so they can argue later that you didn't follow their instructions and therefore they won't replace the battery under Warranty. To keep your battery healthy I recommend to fully charge it, but then use it until lower than 20% before you plug the charger again. If you plan to use the laptop for too long I would disconnect the battery (if you can remove it) and use it with the charger, so you don't have to worry about overcharging it. Also avoid storing a full battery for too many days, as this also reduces its capacity. Store the battery almost empty when not in use for many days.

Hi. Dell Power Manager is integrated in to the My Dell app. If you select "Power" in the app, you will be given details of the battery health, charging/discharging rate (X% per hour) and you can select various charging options - Standard, (When alternated between mains and battery power), Custom, (Min/Max charging levels) Adaptive (machine sets the appropriate charge) and when mostly plugged in to mains. You may have to try the various options to find what's best for your setup.
I believe the Fusion service is required to run My Dell - available from the Dell Drivers & Downloads page for your Service Tag.
Mitch

Forgot to mention than some laptops have a safety feature that stop charging when battery is fully charged, but I wouldn't count on it. It is better to remove the charger when fully charged and connect it again below 20%. In my Fujitsu Stylistic Q702 there wasn't always a warning to plug the charger from Windows 10. I had to use a utility such as Battery Alarm to produce a sound (I didn't had view of the taskbar when watching a movie at full screen). After upgrading to Windows 11 I get the warning in time before the computer turning off automatically and ruin the movie.

spapakons said:

Forgot to mention than some laptops have a safety feature that stop charging when battery is fully charged, but I wouldn't count on it. It is better to remove the charger when fully charged and connect it again below 20%. In my Fujitsu Stylistic Q702 there wasn't always a warning to plug the charger from Windows 10. I had to use a utility such as Battery Alarm to produce a sound (I didn't had view of the taskbar when watching a movie at full screen). After upgrading to Windows 11 I get the warning in time before the computer turning off automatically and ruin the movie.

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It is years since I had any devices that needed this to be done. Most of my devices were left plugged in 24/7 for years with no obvious drop in life.

Sure the batteries have a shorter life after several years but that happens whether plugged in or not.

All the advice you see on internet is same decade+ old advice being regurgitated by wannabe tech journalists.

When was the last time, you saw proper tests being done by a vendor? In my opinion, they like to perpetuate this "urban myth" so if anybody tries to claim on a warranty, they wriggle out of it blaming the user.

Running a 2015 HP laptop as a desktop alternative (always plugged in) I'm on my second battery. No 80% limit software available and it will be needing another one soon unless I recycle it. About 3.5 years battery usefulness.

On an ASUS laptop (ex-display) bought August 2020 and used as a desktop (always plugged in) with 80% software running it's down to 78% health. How fast the health deteriorates faster the lower it gets I have no idea. Not sure with modern laptops if there's actually any benefit at all with the charging limiter but using it nonetheless just in case.

For checking the battery I use Batteryinfoview (Nirsoft) as a quick checker.

My wife hates it when I get out of bed at 2 am every morning to unplug my laptop so it doesn't overcharge the battery. When she grumbles about it I say, "But honey, I read it on the internet!"

cereberus said:

All the advice you see on internet is same decade+ old advice being regurgitated by wannabe tech journalists.

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I agree with cereberus.
There is no publicly-available data to support any particular decision about limiting battery charging.

Several owners of new Dell & HP computers have posted in TenForums that their versions of Dell Power manager & its HP equivalent do not have the charge-limiting facility.
Dell tech support posted a video in which they said that charge-limiting did not have any effect but without posting any data to back up their claim. See my ditty - Dell Tech support video about battery use [post #8] - TenForums

I've been running a trial on one computer for 18 months and intended to analyse the results properly after two years.
- During the trial I have limited charging to 80-90%.
- To quantify battery degradation, I measure the ratio of Last full charge to Design capacity [obtainable from PowerCfg Battery reports & Energy reports].
- A 2016 battery that had degraded to about 60% before the trial started continues to degrade at the same rate as before.
- A 2018 battery that was still at 100% Last full charge to Design capacity before the trial started remains at 100%.


Denis

Try3 said:

I agree with cereberus.
There is no publicly-available data to support any particular decision about limiting battery charging.

Several owners of new Dell & HP computers have posted in TenForums that their versions of Dell Power manager & its HP equivalent do not have the charge-limiting facility.
Dell tech support posted a video in which they said that charge-limiting did not have any effect but without posting any data to back up their claim. See my ditty - Dell Tech support video about battery use [post #8] - TenForums

I've been running a trial on one computer for 18 months and intended to analyse the results properly after two years.
- During the trial I have limited charging to 80-90%.
- To quantify battery degradation, I measure the ratio of Last full charge to Design capacity [obtainable from PowerCfg Battery reports & Energy reports].
- A 2016 battery that had degraded to about 60% before the trial started continues to degrade at the same rate as before.
- A 2018 battery that was still at 100% Last full charge to Design capacity before the trial started remains at 100%.


Denis

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It is really great you are doing something positive.

However, as I am sure you know, it is rather difficult to make a statistically significant conclusion based on a limited dataset.

Statistics theory generally regards 100 tests as minimum to yield definitive conclusions (some claim 30).
Also, really you need control sets i.e. ones plugged in 24/7 with no limit on charging to compare with.

Of course, only the battery/pc companies could do such levels of testing.

However, your tests seem to directionally agree with my assertions - decaying drives are more a function of age than charging regime.

It will be interesting to see your results even if we cannot necessarily make a definitive conclusion.

A more compelling reason to turning off charger when not needed is purely a safety reason to minimise fire risk.

cereberus said:

However, as I am sure you know, it is rather difficult to make a statistically significant conclusion based on a limited dataset.

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Absolutely. I believe that my results will apply only to my computer's battery management system.
But
If the final results were to show a marked slowdown in battery degradation that would imply that there was something worth looking into properly.
[But the interim results really don't look like that].

cereberus said:

It will be interesting to see your results even if we cannot necessarily make a definitive conclusion.

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Yes, I'll info you on the results post.

All the best,
Denis

NavyLCDR said:

My wife hates it when I get out of bed at 2 am every morning to unplug my laptop so it doesn't overcharge the battery. When she grumbles about it I say, "But honey, I read it on the internet!"

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Why not adjust your time to 7 am - you could switch it off one day for 5 hours to adjust the time .

Here's a Battery Status script I wrote that reminds you to stop charging when the battery reaches 80% and plug in when the battery reaches 20%. To download, go to the link and Alt-click the Raw button (or right-click, save link as).

I would not spoil my sleep just to disconnect the charger from my laptop or smartphone. My sleep is more important than avoid damaging a replaceable battery.

spapakons said:

I would not spoil my sleep just to disconnect the charger from my laptop or smartphone. My sleep is more important than avoid damaging a replaceable battery.

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The app's "notification" is silent. No sleep disturbance.

cereberus said:

Why not adjust your time to 7 am - you could switch it off one day for 5 hours to adjust the time .

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Well, actually, my MSI laptop was purchased brand new in 2021. So I think being almost 1/4 into the 21st Century, laptop manufacturers have probably figured out pretty well how to control battery charging so as not to damage the battery, so I think I will just leave it plugged in almost 24/7 and not really worry about it

Maybe you're looking for something similar to ASUS Battery Health Charging.

Stigg said:

Maybe you're looking for something similar to ASUS Battery Health Charging.

View attachment 52486

ASUS Battery Health Charging - Introduction | Official Support | ASUS USA

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We had a customer once with the Maximum lifespan mode switched on and he didn't have a clue how to turn it off anf fully charge the battery. Many users prefer a longer battery duration than a longer lasting battery. Makes sense.