Conversation so far:
what voltage comes out of a wall outlet
Wall outlets in America have two standard voltage amounts: 120 and 240.
what voltage comes out of a wall outlet in asia
Most Asian countries all run on 220/240 volt electricity.
why do asia and america have different voltages
The US wanted to change to a higher voltage, but because of the cost involved to replace all electric appliances, they decided not to.

Question: how about AA battery
Self-contained rewrite: what is the voltage of AA battery