Final answer:
Key-off loads contribute to sulfation caused by prolonged discharge, which can lead to plate deterioration and grid corrosion.
Step-by-step explanation:
Key-off loads contribute to sulfation caused by prolonged discharge. Sulfation is the formation of lead sulfate crystals on the battery plates, which can reduce the battery's capacity and performance over time. When a battery is left in a discharged state for a long period, sulfation can occur and lead to plate deterioration, as well as grid corrosion. Plate deterioration refers to the degradation of the battery plates, leading to reduced efficiency, while grid corrosion is the corrosion of the lead battery grids, which can weaken the structural integrity of the battery.