The correct answer is: C. both (A) and (B).
Internal short circuits are caused by the breakdown of one or more separators, or by excess accumulation of sediment at the bottom of the cell.
Separators are thin sheets of material that are placed between the positive and negative plates in a lead-acid battery. They prevent the plates from touching each other, which would cause a short circuit. If a separator breaks down, the plates can touch each other and cause a short circuit.
Sediment can accumulate at the bottom of a lead-acid battery if the battery is not properly maintained. This sediment can cause a short circuit by conducting electricity between the plates.
Both of these problems can cause internal short circuits, which can damage the battery and lead to premature failure.
Here are some additional details about each of the options:
- Option A: Breakdown of one or more separators. Separators are thin sheets of material that are placed between the positive and negative plates in a lead-acid battery. They prevent the plates from touching each other, which would cause a short circuit. If a separator breaks down, the plates can touch each other and cause a short circuit.
- Option B: Excess accumulation of sediment at the bottom of the cell. Sediment can accumulate at the bottom of a lead-acid battery if the battery is not properly maintained. This sediment can cause a short circuit by conducting electricity between the plates.
- Option C: Both (A) and (B). Both of these problems can cause internal short circuits, which can damage the battery and lead to premature failure.
- Option D: None of the above. None of the other options are correct.