Cycling brand new batteries helps to increase their lifetime, achieve a closer balance between cells, and maintain a lower internal resistance. A typical battery cycle involves the process below. 5-10 cycles are recommended for best results. Batteries typically normalize after 10 flights, and last much longer than batteries that have not been cycled and instead ran hard from their very first flight.
1) - Balance charge the battery to full. The cells should be 4.18v-4.20v each. Balance charging requires both the battery's power wires (red and black wires) to be plugged into the charger, as well as the white balance connector.
2) - Fly the battery in an airplane for half the normal flight time. Try not to overwork the battery and/or use full throttle for too long. You should be landing at near the 50% capacity level. As an alternative to flying an airplane, you can also slowly advance throttle to the airplane held down on the ground. Don't overheat the motor by running it too long or too hard. ~25% throttle for one minute intervals, with one minute breaks in between to cool down, is a safe margin.
3) - Once the battery is down to ~50% capacity, balance charge the battery again.
4) - Repeat these steps 5-10 times. Your battery's cells should normalize up to 4.19v-4.20v across the board.