I was looking for techniques to make pancake batter the night before and I came across this link.
They suggest that we add extra leavening agent.
I decided to follow the usual recipe for pancake batter, and just add the baking soda and baking powder in the morning. Although there is risk of overbeating to mix the baking powder evenly, I felt it is better than adding too much leavening agent.
The other technique is to mix the dry ingredients with egg and melted butter and refrigerate the mix. In the morning add the leavening agents to the milk and mix it with the batter.
Ensure that you use up all the batter in the morning. The pancakes can be frozen if necessary and then thawed before serving. Check this link out for tips on freezing the pancakes.