Red Seal Electrician Practice
Safety and work practicesQuestion 787 of 1506

What happens to a lead-acid battery that is overcharged?

  1. The battery stores extra amp-hours
  2. The water in the electrolyte breaks down and the battery life is shortened
  3. The cell voltage doubles and the capacity is lost
  4. The acid turns to solid lead and the battery stops working at once
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Correct answer: The water in the electrolyte breaks down and the battery life is shortened

Overcharging causes electrolysis of the water, which also makes hydrogen gas.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 11.5: Practical Considerations - Batteries

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Questions last reviewed: 18 October 2026