Can I use 20W USB-C Power Adapter to charge my MacBook Air M2, 2022?

The battery “reservoir” in a MacBook gives you the flexibility to use “underpowered” power adaptors.

I travel almost exclusively w/ a 20W block for a MBP … but I generally also have a 120 VAC source available as well.

It keeps the battery’s State of Charge (SoC) fairly stable when running “Office” type apps; the SoC slowly falls when running more power-intensive apps or teleconferencing; and slowly climbs while “idling” with a simple monotone lock screen.

You’ll easily learn how your own hardware behaves.

It won't hurt to try and use the 20W adapter, but charging will be significantly slower.

If you want to use fast charging, you will need a 70W adapter.