Question Laptop sometimes charges when plugged in, sometimes it doesn't ?

[edamiani]

Hi, I recently bought a refurbished Asus Z13 laptop. I noticed that sometimes the battery is drained when I'm playing games, even when the notebook is plugged in. The laptop came with a 100W charger which should be enough to hold a gaming session. The problem is that sometimes it works fine: I can play a game and the battery isn't drained at all, but I can't find a pattern for it.

I spoke to Asus support, which wasn't really helpful, and I already tried these things:
- Window 11/driver update.
- Bios/firmware upgrade.
- I bought a second, identical charger to see if the problem would disappear (it didn't).
- Connected the notebook to different outlets.
- Drained the battery and recharged it.
- Pressed the power button for 30+ seconds.
- Tried to disconnect/reconnect the charger (it uses a USB-C port).

I also generated some reports using the powercfg command line but I couldn't find anything suspicious.

Is there anything I could try or should I admit defeat and send the laptop for repair?

Thanks in advance!

 

[JohnBonhamsGhost]

it's possible that the USB-C port just isn't holding a firm connection at all times.

wait until you notice a time while it is plugged in but not showing the charging process.
then try manipulating the cable in it's port and see if the charge initiates.

 

[edamiani]

it's possible that the USB-C port just isn't holding a firm connection at all times.

wait until you notice a time while it is plugged in but not showing the charging process.
then try manipulating the cable in it's port and see if the charge initiates.

Hi, thanks for your answer. I tried your suggestion but it didn't work. The funny part is that the battery icon shows that it's charging, even when it's not.

 

[edamiani]

I kept doing some tests and I think I've hit something interesting there. I recently bought a USB-C power meter to see if I could gather more information about it. What I found out is that the notebook is correctly receiving 20V but, usually, it caps on 1.5A when it could use up to 5A. This means that the charger is sending around 35W max when it could send up to 100W on 5A.

(Both of my chargers show this behavior so it's unlikely that the problem is the charger itself).

However, I've found a hack around it: if I reconnect the charger when I'm playing a game, the charger will move beyond the 1.5A cap and will start charging the notebook as it should. If I quit the game and the needed charge goes back to below 1.5A, the charger gets stuck on 1.5A again and I need to do the hack once more to unlock its full power. This behavior is 100% reproducible.

From this information, would it be possible to infer if this is a hardware issue or a BIOS/firmware bug?