Which of the following is NOT a root cause of ESS battery failures?

• A. Mechanical damage
• B. Overcharging
• C. Software updates
• D. Thermal abuse

Answer: (C)

Software updates are not a root cause of ESS battery failures. The failures typically stem from physical or electrical stress on the cells: mechanical damage (impact or crushing that damages internal cell structure and can cause short circuits), overcharging (exceeding the designed voltage can drive abnormal reactions and gas buildup, leading to swelling or thermal runaway), and thermal abuse (excess heat or poor cooling accelerates aging and can trigger dangerous reactions). The battery management system uses software to control charging, temperature, and safety interlocks, and when updates are done correctly, they help prevent failures. A faulty update is not itself a fundamental cause of battery fires or degradation; the underlying issues come from damage, improper charging, or heat exposure.