A common cause of NiCad battery overheating is

• A. Overcharging
• B. Over discharging
• C. Regular cycling
• D. Short circuit

Answer: (A)

Overcharging is the typical reason NiCad batteries overheat. When a NiCad cell is charged beyond its full capacity, the charging current continues to drive chemical reactions inside the cell, which wastes energy as heat. In addition, overcharge causes gas formation inside the cell, raising internal pressure and accelerating temperature rise. Prolonged overcharging or fast charging amplifies these effects, leading to noticeable overheating and potential venting.

The other scenarios don’t fit as the common cause during normal operation. Over discharging damages the cell and reduces performance, but it doesn’t usually cause overheating during charging. Regular cycling is normal and not inherently overheating. A short circuit would cause rapid, extreme heating, but that’s a fault condition rather than a typical charging-related cause.