When does a storage battery become faded?

A storage battery becomes faded primarily when it is discharged. The process of a battery discharging involves the conversion of chemical energy into electrical energy. As this energy is used and the battery approaches its lower charge levels, the active materials inside the battery can degrade, leading to a condition known as "fading." This degradation often results in a diminished ability to hold a charge and can lead to permanent damage over time.

In contrast, when a battery is fully charged, it is in a state where it is ready to deliver energy efficiently. High temperatures can indeed negatively affect battery performance, as they may accelerate chemical reactions that can lead to faster degradation; however, this does not directly define the fading of a battery. The use of aged cables may also introduce resistance, affecting the ability to charge or discharge effectively, but it does not define the fading condition of the battery itself. Therefore, the primary reason a battery experiences fading is linked to being in a discharged state.