This article is from the Mongolia FAQ, by Oliver Corff with numerous contributions by others.
All these electric things are mentioned here. Do they operate on
batteries? No, of course not. The standard electrical voltage of
Mongolia is 220V, 50 cycles/second, and is supplied via Russian-style
electricity outlets. The connector pins are round, usually with a
diameter of 4mm, so squeezing modern German 5mm plugs into Mongolian
sockets will break the socket. Either retrofit your wiring with so-
called European plugs (4mm, no earthing connector), or use adapters,
or modify or replace the wall outlet.
Electricity is available in the cities of Mongolia as well as in aïmag
centres and larger villages; in the countryside however, solar-driven
batteries are extremely useful.
Prepare yourself for brown-outs (unstable electricity supply) and
black-outs (complete electricity failure) at unregular intervals for
everything between fractions of a second and several hours.