No Wireless charging and Fast Charge do not work on the A3.

@SSpreitzer The A3 should actually be able to use a large portion of the US frequencies used on AT&T (2G, 3G and min 1 LTE 4G band) and T-Mobile (2G, 3G & min 1 LTE band) , Verizon (min 1 LTE band) and thus be usable for the US.... For the other numerous providers, no idea. The respective network coverage is not always given, especially in more remote areas. But basically it works.

The battery is not removable, so it is not possible to replace it yourself.

Hello, yes it is quadriband, you just need to put a Swiss sim card first to unlock it.

Android has a built-in cloud backup that can transfer certain things to the new device, and if you activate it, the backups are made at night when the phone has power and Wi-Fi. There is also an app from Samsung. Certain apps like Whatsapp can export their data to the microSD card for migration. And files can generally be transferred from the microSD card to the new device. Personally, I haven't used the Samsung app because the reviews aren't that good.

Hello Cmk, Yes it has. You can find it in the specifications under "Interfaces" 3.5mm jack socket 1x Greetings