Where to start...
First of A+ and Network+ certifications have absolutely nothing to do with the principles of electrical engineering and or theory.
Second, mAh wont make a difference. The only thing that matter is that the voltage coming out of the pack stays the same. By that logic as long as each cell outputs the same voltage as before you shouldn't have a problem.
Cant figure that out? Take the cell's output voltage (should be listed on the battery casing) and divide it by the number of cells in the battery. Thus giving you the voltage output of each cell.
Make sure though that when you replace the cells that they are at least as powerful mAh wise as the previous ones, otherwise that **** thing won't get **** for battery life.
*I cannot be held responsible for any damage you may cause to: yourself, your laptop, or the cells.*