The scientists created models to predict how well fuel cells work in different temperatures. They made one model for the fuel cell itself and another for a group of fuel cells. The models were good at predicting how the fuel cells worked at low temperatures. But they need to improve the models for high and very low temperatures. The data helped them figure out how to control the temperature inside the fuel cell group. They found that the fuel cells worked best at around 60 degrees Celsius. The models can help make the fuel cells lighter and more efficient.