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Laptop battery started draining quickly below 40% - hardware or software issue?

180 Views 9 Replies 5 Participants Last post by  plodr
Windows 10 laptop, 2.5 years old with its original 48 mWh battery installed. Up until recently the battery has always performed well and typically took around 2 hrs to charge from flat to full.

A few weeks ago I suddenly noticed issues where the battery would unexpectedly be critically low when waking the laptop from Sleep mode after several hours (e.g. overnight). Further testing has shown that this often happens when I put the laptop into Sleep OR Hibernate mode when the battery is 30-40% full or less - when I wake it up it's suddenly empty, or other times it shows ~60% and then rapidly drops to empty over a few minutes. It seems not to do it as often if I sleep/hibernate it with the battery mostly full, although today it showed a drop from around 60% to 40% after being in Sleep for 18 hrs. On the other hand, if I charge it to 100% and shut it down completely, it seems to hold charge OK and will still be ~98% when I boot it up in the morning.

I've been generating a lot of battery reports (powercfg /batteryreport) but having trouble interpreting the erratic results. "Full Charge Capacity" seems to fluctuate a lot from day to day. I am pretty sure it charges fully to ~48 mWh, regardless of what it thinks the "Full charge Capacity" is, because it still takes about 2 hrs from flat before the orange LED on the front turns green (even if the system tray icon sometimes says "5 min remaining to full charge" for the last 20-30 min and the battery report ends up >100%). This makes me think the software battery monitoring is out of calibration. But I have tried the whole full charge/full discharge/full charge cycling thing and I don't know what to do next to test whether this is purely a software issue or if the battery really is failing.

Following internet advice I also removed the device "Microsoft ACPI-Compliant Control Method Battery" and reinstalled it a couple of times. This doesn't seem to have made much difference.

What should I try next to help diagnose the problem?

Tech Support Guy System Info Utility version
OS Version: Microsoft Windows 10 Pro, 64 bit, Build 19045, Installed 20210607014636.000000+660
Processor: Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz, Intel64 Family 6 Model 165 Stepping 2, CPU Count: 12
Total Physical RAM: 16 GB
Graphics Card: Intel(R) UHD Graphics, 1024 MB
Hard Drives: C: 930 GB (492 GB Free); D: 931 GB (589 GB Free);
Motherboard: IT Channel Pty Ltd NP50DE_DB, ver Not Applicable, s/n Not Applicable
System: INSYDE Corp., ver INSYDE - 2, s/n NKNP50DB0000I00274
Antivirus: Windows Defender, Enabled and Updated
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When you leave your laptop on sleep mode you are using the battery and that is why it drains up too quickly. The best solution may be to plug it into the power outlet of your house or work or turn it off when not in use.
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...Yes, I am aware that Sleep mode uses a small amount of battery power.

Do you have any responses to the situation that I wrote about in my post?
Not sure what programs may be running on the background. Maybe the battery may be going bad too.
Thanks - I'll take that as a no.

Anybody else?
Most likely you’re battery is going bad
Download and run this
It is a small, no install and his programs can be trusted. I run several of them.
Look at 3 items: Designed capacity, Current capacity value and Battery health.
My battery health is down at 31% because it is a 10 year old laptop. When I run on battery, it incorrectly states it will last a few hours; it shuts off around 20 minutes or less.

If you use it on battery a lot, it probably needs a new battery.
I would agree that the most likely situation is that the battery may be degrading. You should be able to tell by the battery report where you see the design capacity and the full charge capacity. Can you please confirm these values?

A side note, my previous employer had a power policy where somehow even though users were putting the computer to sleep, it was only turning off the monitors. Can you please confirm what policies you do have?
Thanks plodr and Couriant. The "Sleep" instruction is definitely sending it to sleep. The batteryinfoview utility seems to show mostly the same info as the powercfg battery reports (not surprising I guess). Battery health is 84%. Design capacity is 48260 mWh and full charge capacity is today showing 40675 mWh, but over the past few weeks has fluctuated daily anywhere between 35k and 45k which is why I just don't know if the battery monitoring is trustworthy. Hence my question about if there's any other ways to distinguish between issues with the physical battery vs issues with the battery monitoring functions within Windows. The problems just seemed to start so suddenly that they make me think more of a software update breaking something than my idea of a battery's physical health declining gradually over time. But maybe I've got the wrong idea and that's how they fail.

I'm also less worried about the full charge capacity than the rapid unexpected discharge below 30-40%.

If you use it on battery a lot, it probably needs a new battery.
I'm a little surprised to hear this, can you please elaborate? My first laptop's battery faded after 4-5 years, I used it on AC power all the time so the battery was pretty much always topped up at 100% except on rare occasions when I travelled somewhere. Later I was led to believe that Li-ion batteries do better when they're cycled rather than constantly on trickle charge so these days I use my laptop on battery until it gets low(ish) and then charge it up again. Which approach is supposed to be better?
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Batteries last based on the number of charges/discharges not by years it is in the device.

I have an ancient eeepc from January 2008. It was used mostly plugged in. Believe it or not, I can still use it without being plugged in. The last time I tested, it lasted close to an hour.

84% is good so I doubt whether the battery needs replacing. Something else is going on if that number keeps fluctuating. Have a look at the contacts between the laptop and the battery.
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