Basic Automotive Electrical Diagnostics Practice Test 2025 – The Complete Guide to Master Electrical Diagnostics!

Sulfation of battery plates occurs when lead sulfate crystals form on the battery plates, typically due to a lack of regular charging or prolonged periods of inactivity. This process is detrimental because it reduces the effective surface area of the lead plates, which is crucial for the chemical reactions needed during charging and discharging cycles. As a result, the battery's ability to hold and deliver a charge decreases, leading to reduced overall battery capacity.

When sulfation occurs, the internal resistance of the battery increases, making it less efficient in both storing and providing power. This diminished capacity can manifest as a battery that fails to start a vehicle or does not hold a charge for as long as it should. Regular maintenance, including routine charging, can help prevent sulfation and prolong battery life, but once significant sulfation occurs, the capacity can be severely compromised.