Shunt Order This option controls the highlighting in Red of the cell voltage bars on screen 1. A Red battery voltage bar indicates that the Shunt is active for that cell. Shunts are small resistors that can be switched in to drain a small amount of energy from one or more of the 96 cells that make up the high voltage battery pack. This is the method used by Nissan to balance the pack by draining energy from the high energy cells. This works because charging stops to prevent overcharging the highest energy cell. So by reducing the energy in the highest energy cell all the other cells are able to be charged to a higher level.