GROL Power Sources and Distribution 3

Question 1

What is the nominal voltage of a single cell in a fully charged lead-acid battery?

Accepted Answer

2.0 volts per cell

Answer

Each cell of a fully charged lead-acid battery has a nominal voltage of approximately 2.0 volts, so a 12V battery contains six cells in series.

Question 2

What is the primary operational advantage of lithium-ion batteries over lead-acid batteries in marine applications?

Accepted Answer

Higher energy density and significantly lighter weight for the same capacity

Answer

Lithium-ion batteries store significantly more energy per pound than lead-acid, making them ideal for weight-sensitive marine installations.

Question 3

Which charging method is specifically recommended for nickel-cadmium (NiCd) batteries to prevent overcharging damage?

Accepted Answer

Constant current charging with a reliable termination method

Answer

NiCd batteries require constant current (CC) charging because their relatively flat discharge curve makes voltage-based termination unreliable.

Question 4

When using a hydrometer to check a lead-acid battery, what specific gravity reading indicates a fully charged cell?

Accepted Answer

1.265 to 1.285 (fully charged)

Answer

A fully charged lead-acid battery cell has electrolyte with a specific gravity of approximately 1.265 to 1.285.

Question 5

What is the primary purpose of applying a periodic equalization charge to a flooded lead-acid battery bank?

Accepted Answer

Balancing cell voltages and dissolving early-stage lead sulfate crystal buildup

Answer

Equalization applies a controlled overcharge that balances individual cell voltages and reverses early sulfation, extending overall battery life.

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