I realize that this can be determined mathematically by using the Nernst equation, and that the change in the cell voltage on changing the ion concentrations will be determined by the change in the log term of the Nernst equation, but I was wondering if there was a more general way to determine how the cell voltage can be changed upon increasing or decreasing ion concentrations, without having to do any calculation? Would the Le Chatelier's principle have anything to do with it?