This is the difference in price between a lipo like an Orion for example and a lipo off Ebay thats less than 1/2 the price. In the better lipos, the cells are closely matched and in Kokam's case their manufacturing process from the start is geared toward producing cells of near identical character. Better quality cells will tolerate more abuse (discharging to a higher percentage of capacity, doing it more often and slight overdischarges) than lower quality cells.

Have to be more careful with cheaper lipos than with higher quality lipos. Don't get me worng, you can damage the better quality lipos too, but its usually not fatal (don't swell) - you just get fewer cycles from them.