[agurk]

I assume it's proprietary (are there even standards for this kind of connector?).

The charger body has two fixed pins inside a circular collar with two tabs on it that the tip is placed over then rotated 45 degrees to lock.

[p1mrx]

It's pretty common to use IEC C7/C8 for the PSU<->AC connection:

https://en.wikipedia.org/wiki/IEC_60320#C7/C8_coupler