My MacBook Pro can undergo 1000 charge cycles (using up the battery completely and charging it back to 100%) before the battery's life is reduced to 80% of what it originally was.
Obviously, using high brightness while the computer is plugged in speeds up the rate of battery discharge, causing you to plug in the computer sooner and thus use up charge cycles faster. However, if I were to increase the computer's brightness during charging, or up the energy usage in any other way, wouldn't the process of charging slow down, the time between charge cycles would increase, and thus the long-term battery life would increase?
In other words, does increasing energy usage during charging actually increase battery life?