Over charging

produces excessive gassing
loosens the active material
increases the temperature resulting in buckling of plates
all above

The correct answer is D. all above.

Overcharging a lead-acid battery can cause a number of problems, including:

  • Excessive gassing: This can lead to the formation of hydrogen gas, which can be explosive.
  • Loosening of the active material: This can cause the plates to buckle and the battery to lose capacity.
  • Increased temperature: This can cause the battery to overheat and damage the internal components.

To avoid these problems, it is important to charge a lead-acid battery properly. The charging voltage should be set to the correct level and the battery should not be left to charge for too long.