I am working on room temperature sodium sulfur batteries. For a CNT/S based cathode with 0.1 C rate, I am calculating the corresponding current as follows:

Current = (0.1)* [(mass of coated foil - mass of bare foil) * active material]*(percentage of sulfur/100) * 1675.

I am calculating the current with this formula and running the cells. In the cells, the total time taken for the cycle should be 10 hours (5+5) as per my understanding. But, I am getting a total time of 7 hours. I am confused if I am calculating the current wrong or interpreting wrongly. Please help me