Why can't I turn on my laptop on battery while my battery can give 3 hours of usage?

[Brian_Sebastian]

System: Windows 10
Battery or AC: Battery
Model: ASUS Vivobook A442U
Frequency of occurrence: Often
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Detailed description：
If I try to startup my laptop on battery, It will only turn on until the user screen (the one with your name and password) and then my laptop dies like it ran out of battery. I thought there was a problem with my battery but I can still get 3-4 hours of laptop usage on battery only after I finished the startup and unplug the charger(used charger to start up the laptop).
Is there anything faulty in my laptop?
For additional Information : My laptop is around 1,5 - 2 years old

[Blake_ASUS]

Hello Brain,
When you boot your device in Battery mode, how many % of battery is it?
Thank you.

[Brian_Sebastian]

Around 80 - 100%

[Blake_ASUS]

Hello Brain,
And before you boot it, how long you have not been using the device?
Thank you.

[Brian_Sebastian]

I don't use it during overnight, around 8-9 hours