Is battery mAh measured per cell?

Solution 1:

The battery pack's capacity rating is for the entire pack, not just a single cell.

Solution 2:

There's no difference. A 4-cell, 14.8V lithium pack consists of four 3.7V lithium cells connected in series. Since they're connected in series, the same current flows through all the cells. So when you've drawn some number of mAh out of the pack, you've drawn that same amount of mAh from each cell as well.

Think of it like a line of men relaying heavy rocks up a hill. If you add men, you still move the same number of rocks, you can just move them up a bigger hill. The cells connected in series all carry the same current just like the men on the hill each move the same rocks. The four men let you move the rocks over a bigger hill, just as the four cells let you supply a larger voltage.

Keep in mind, mAh is a measure of capacity, not power. A measurement of mAh is like a measure of how many rocks the men can move. If each man can move X number of rocks, the row of four men can move X number of rocks.

To get the energy capacity of a pack, multiply the voltage by the mAh rating. Note that this isn't perfect, especially when comparing packs by different manufacturers, because they don't use perfectly consistent methods of measurement.