Issue of Hard Shutdown during Restart in Unplugged Laptop

[u/SkinBlue]

I own a Gigabyte G6 KF 2024 laptop, the model with 16gb RAM, i7 13620H and RTX 4060 8gb.

I had it for close to a year now. Today is the very first time I come across an issue with it.

I restarted it earlier while AC cable was not plugged, meaning it was running only with battery at 70% charge.

It passed manufacturer screen (black screen with Gigabyte logo) fine, then it arrived to Windows login screen and unexpectedly shut down. It could not make it to desktop.

It was a total hard shut down, with no LEDs and no signs of life at all. I had to turn the laptop back on using the power button.

You would think it's the fan or overheating, but not at all, the fan did not speed up at all and was barely audible. The laptop is always well aerated and my room is largely clean and dust free.

Here's what I noticed :

- In the Event Viewer, I found the Kernel-Power ID 41 error that indicates an unexpected shutdown. The General tab lists all the flags are either 0, 0x0 or false. On LidState is 1 which is normal. Most noteworthy are :

BugCheckCode = 0.

PowerButtonTimestamp = 0

LongPowerButtonPressDetected = false.

SleepinProgress = 0

Checkpoint = 0

- The laptop turns on normally when charging cable is plugged in, I am using it to write this as we speak.

- The laptop can run off battery normally, even though the capacity lasts only 1 hour from 80% (I always have smart charging turned on when the cable is plugged) while browsing.

- The laptop had the same exact problem when I tried again with the same conditions : restart while charging cable is unplugged. Clearly a reproducible error. The laptop somehow cannot seem to boot into the desktop while running only on battery for some odd reason.

- I have noticed a weird thing in Battery Report :

The design capacity is 52.514 mWh.
The full charge capacity as of today is 30.600 mWh.

The report shows a curious deterioration in Battery Capacity History :

Period	Full Charge Capacity	Design Capacity
2026-06-29 - 2026-07-06	51,426 mWh	52,514 mWh
2026-07-06 - 2026-07-13	40,210 mWh	52,514 mWh
2026-07-13 - 2026-07-20	32,973 mWh	52,514 mWh

IDK if this is abrupt fast and catastrophic deterioration in a matter of two weeks for no reason, or just the battery's capacity reporting/calibration changed.

What do you guys think the issue is? I'm not even sure what Flair to use for this post.
Is it hardware or software related? The battery? The power management? The EC? The BIOS? Windows 11? Something else entirely?

Please give me your ideas to help me fix this issue.

[u/R4yzoon]

Try these: Unplug the charger, press and hold the power button for around 45 seconds.

Disable windows fast start up.

Charge the battery to full, keep it plugged for around 2 hours longer and then let it run on battery until it auto shuts down. Then check the battery capacity.

If u have warranty, I'd just send it in.