Hardware Weird Laptop Battery Fluctuations

[Jiehfeng]

I have a Xiaomi Air 13 (2017) laptop and the battery life of mine is horrible, or so I think it is.
Most of the time, with airplane mode on, brightness at 50%, battery set to the level just above power saving mode on Windows 10, and using the integrated graphics, playing a 1080p video for instance gives me about 2 hours of battery life.

But sometimes, under the same circumstances and settings, I get 4 and a half hours of runtime. It varies from time to time after every charge session (to full of course), and either get very good battery life like about 4 and a half hours, or only about 1 hour and 50 minutes.

And this is all doing the same thing; watching 1080p videos with VLC with the settings mentioned above.

I noticed another something very weird as well.
When I was done watching and had 2 hours and 30 minutes remaining of battery life, I opened paint to paste a screenshot and save it. Immediately after I checked the estimate, it said 1 hour and 30 minutes.
Just like this I noticed if I for example turn on WiFi, browse for a minute, and then go back to airplane mode. My battery life of 4 hours reduce drastically to about 1 or 2 hours minutes later.

Also please note these are not just Windows estimates, my laptop runs for the same amount of time estimated as I use it and I time it. The estimates are very accurate as well anyway.

So basically my laptop battery life seems to fluctuate under the same kind of usage.
What can cause such behavior and how can I fix this?
Thanks in advance.

 

[spinal_cord]

Remaining battery time is only an estimate and only based on what kind of stress the computer is under at the time of that estimate. If at the time the computer guesses your battery life it is idling and doing almost nothing, then the guess will be a longer time based on your computer doing nothing, but if the computer is loading a program for example, then the cup and ram usage goes up, if at this time the estimate of remaining time will be much lower.
It's a similar situation you have when copying files. the estimated time is based on how many files are left to copy and how long it took so far. Because different files take different amounts of time to copy, then the time fluctuates up and down during the process.

 

[Ryccardo]

It's a similar situation you have when copying files. the estimated time is based on how many files are left to copy and how long it took so far. Because different files take different amounts of time to copy, then the time fluctuates up and down during the process.

https://everything2.com/title/Microsoft+time

 

[Jiehfeng]

Remaining battery time is only an estimate and only based on what kind of stress the computer is under at the time of that estimate. If at the time the computer guesses your battery life it is idling and doing almost nothing, then the guess will be a longer time based on your computer doing nothing, but if the computer is loading a program for example, then the cup and ram usage goes up, if at this time the estimate of remaining time will be much lower.
It's a similar situation you have when copying files. the estimated time is based on how many files are left to copy and how long it took so far. Because different files take different amounts of time to copy, then the time fluctuates up and down during the process.

Please read my whole post. It is not just the estimates, I have used my laptop for 4 1/2 hours and then 2 hours both doing the same task not considering any estimates, just how long I used it till the battery almost drained.
Also about the estimates, as I said in the OP, while watching the movie the estimate said 2 hours, but as I opened paint it said 1. But please don't talk about the estimates here, this is not the issue.

 

[spinal_cord]

but, does you battery last as long as the estimated time? Opening even one extra program will greatly effect how much work your computer is doing and therefore how long the battery will last. Especially with modern software that does not focus on optimising hardware performance. Paint (the example you gave) might seem like a small program, but I bet it wastes a lot of resources. Even the room temperature can effect how efficiently your computer is running.
I never look at the estimated time of my remaining battery, only the percentage, as a rule of thumb, I consider 2 hours on battery to be a good amount of time.

 

[Jiehfeng]

but, does you battery last as long as the estimated time? Opening even one extra program will greatly effect how much work your computer is doing and therefore how long the battery will last. Especially with modern software that does not focus on optimising hardware performance. Paint (the example you gave) might seem like a small program, but I bet it wastes a lot of resources. Even the room temperature can effect how efficiently your computer is running.
I never look at the estimated time of my remaining battery, only the percentage, as a rule of thumb, I consider 2 hours on battery to be a good amount of time.

Yes it does surprisingly. Some sessions I get to watch 4 episodes of GoT (50 mins) and sometimes only 2, and it's the same as what the estimate said, just slightly off by about 10-20 minutes.
But paint only ran for about 30 seconds, how could that have such a massive impact?

 

[Originality]

Open up command prompt and enter the following command:

powercfg /batteryreport

This will save a battery report to your windows folder. If you upload that here, I can review it and let you know what your battery health is really like.

 

[Jiehfeng]

Open up command prompt and enter the following command:

powercfg /batteryreport

This will save a battery report to your windows folder. If you upload that here, I can review it and let you know what your battery health is really like.

Here you go: https://drive.google.com/file/d/1_4AcDuCBzm-HRaGfBWnm_JtBgENmODmo/view?usp=drivesdk

Also note that everything done this year in May/June is the same thing, 1080P VLC like I said in the OP.

 

[Originality]

Never heard of Timi TM1604 before (it's the real name of the Xiaomi), but anywho...

Your battery is at around 75% health.
There's a weird period from February to May where it looked like the battery died, but then it seemed to re-calibrate itself and got back to normal. Maybe you just didn't use it during that time?
Going over the last 3 days, you drained the battery 91% in 2 hours, 11% in 2 hours, 56% in 2h40, and 59% in 1h30.
Based on this, the battery looks fine to me.

Now what could explain the difference in how long the battery lasts is what the system is using to handle each task it's doing. A quick spec search tells me it's got a 7th Gen Intel CPU with a nVidia MX150 (Optimus compatible). If a task demands any amount of GPU acceleration, the MX150 likely kicks in which doubles power consumption. If the task is more CPU intensive or very light on GPU usage, it probably defaults back to the Intel HD Graphics 620.

Some people prefer to disable Optimus and either manually enable the nVidia GPU when gaming, or set up their games to launch with the GPU (so the Intel is the default graphics in all other cases). I've never had an Optimus laptop myself so I can't advise further than that.

 

[Jiehfeng]

Never heard of Timi TM1604 before (it's the real name of the Xiaomi), but anywho...

Your battery is at around 75% health.
There's a weird period from February to May where it looked like the battery died, but then it seemed to re-calibrate itself and got back to normal. Maybe you just didn't use it during that time?
Going over the last 3 days, you drained the battery 91% in 2 hours, 11% in 2 hours, 56% in 2h40, and 59% in 1h30.
Based on this, the battery looks fine to me.

Now what could explain the difference in how long the battery lasts is what the system is using to handle each task it's doing. A quick spec search tells me it's got a 7th Gen Intel CPU with a nVidia MX150 (Optimus compatible). If a task demands any amount of GPU acceleration, the MX150 likely kicks in which doubles power consumption. If the task is more CPU intensive or very light on GPU usage, it probably defaults back to the Intel HD Graphics 620.

Some people prefer to disable Optimus and either manually enable the nVidia GPU when gaming, or set up their games to launch with the GPU (so the Intel is the default graphics in all other cases). I've never had an Optimus laptop myself so I can't advise further than that.

Ah, I see. My GPU is set to use the integrated GPU by default and the laptop will use the MX150 if I set it manually, and I made sure while playing the videos to check task manager and always only the integrated graphics was used.

But isn't the battery weird? For playing the same kind of 1080p videos on VLC with the same brightness settings and airplane mode, one session lasts 2 hours, the next only 11% went down in 2 hours which means I had more than 2 hours left, and then 56% in 2h40 means I have about more than 1 hour remaining. How can there be this fluctuation when I'm literally doing the same thing and not changing a thing on the laptop?

The weird period is when I tried to replace the battery, but the battery I got as a replacement was apparently a fake and the laptop didn't recognize it even though it powered the laptop.

In any case I'm getting a replacement battery soon, hopefully these issues might be resolved by that. Thanks for the help!

 

[Originality]

Even if you’re doing the save task each day, it doesn’t mean that Windows is doing the same thing in the background each time. Defender scans, indexing, data maintenance, Windows update scans and any number of other background tasks could take place and have an impact on the battery. The more apps you have installed, the more likely some or all of them are going to pull some data every now and again.

There’s also a chance that it might be broadcasting your info to China. That’s a joke.

 

[Jiehfeng]

Even if you’re doing the save task each day, it doesn’t mean that Windows is doing the same thing in the background each time. Defender scans, indexing, data maintenance, Windows update scans and any number of other background tasks could take place and have an impact on the battery. The more apps you have installed, the more likely some or all of them are going to pull some data every now and again.

There’s also a chance that it might be broadcasting your info to China. That’s a joke.

Please see this;


Skip to 13:04

It's the same exact laptop but has more than 200% battery life than mine. I just replaced the battery but I'm getting about the same results as before. There must be something wrong here, drivers or something. I really really want to fix this.

 

[Jiehfeng]

I can't believe it, I actually fixed it!!! No one has any idea how happy I am right now.
I just formatted the laptop and reinstalled windows, and then installed the official drivers from Xiaomi's website for this particular model and now my battery lasts 7+ hours!!! I just watched a 1080p video which lasted an hour, and my battery is still at 83%, this is great.