A charge cycle refers to the process of charging a battery from a low state of charge to its full capacity and then discharging it back to a low state. This cycle is crucial for understanding how batteries, such as those in smartphones or electric vehicles, perform over time. Each complete charge and discharge counts as one cycle. Batteries have a limited number of charge cycles before their capacity diminishes significantly. For example, a typical lithium-ion battery can endure around 300 to 500 charge cycles before it starts losing its ability to hold a charge effectively. Proper management of charge cycles can extend the lifespan of batteries.