Recently I'm looking for all in 1 Gan Charger. I don't have to bring 2/3 adapters to travel around everyday.
My concern is GAN Charger, would it damage laptop's battery health.

no issue

most gan usb chargers do not have earthing. so, some laptops with metal casing can give you a buzz

I have been using more than 2 years, no issue at all.

My wife is using it with her macbook for years, no problem.

So long as your laptop has a PD USB-C port and you get the right charger / cable, no problems at all

Which laptop charger got earthing?

Those old2 round DC barrel plug also no earthing since its purely the +ve and -ve DC power connection...
Afaik only desktop got earthing

No difference from laptop pov. At the end of the day its just DC voltage going into your battery...

Just make sure you get the right wattage for your device(s)

I'm using Acer Swift 3 , these details



i'm using this adapter



I'm plan to buy this GAN Charger

seems like not enough juice, and voltage not same also

Based on the original charger, you need a Gan charger capable of minimum 65W on the USB-C1 port

Looks like your laptop wants a 65W USB-PD Charger

the charger you posted would work, BUT, 65W is only if you dont use the other ports, would recommend getting a 100W one so that you have 35W left over to charge your other devices such as your phone

More like device issue, I have one android device has some electrical leakage due to its metal casing,
Only the particular device has issue, other pretty much don't feels a thing

Not buzzing feels but teeny bits of tingling feels