If I know right i can use maximum 30 votes in day. How can i get
Vox Populi badge when it needs 40 votes:
Vox Populi Used the maximum 40 votes in a day.
This is covered by this MetaStackoverflow Q&A
... plagarising unashamedly....
This is totally by design...
If 1 in 3 of your votes are on questions, you will get 40 votes.
If you vote on less questions than that you will get less (lowest is 30)
... and Jeff Atwood has a great blog - its well worth a read.
So how do we encourage people to remember the questions when voting? Perhaps we should institute a new policy: every time you forget to vote a great question up, or a bad question down — a kitten gets it!
... but he is only kidding... honest!