EGSA Battery and Starting Systems

Question 1

What does the Cold Cranking Ampere (CCA) rating of a battery indicate?

Accepted Answer

The current the battery can deliver for 30 seconds at 0°F while maintaining at least 7.2V

Answer

CCA is defined as the discharge load in amperes that a battery can sustain for 30 seconds at 0°F (−18°C) while maintaining a terminal voltage of at least 7.2V for a 12V battery.

Question 2

What is the correct specific gravity reading for a fully charged lead-acid battery cell at 77°F (25°C)?

Accepted Answer

1.265 to 1.285

Answer

A fully charged lead-acid battery cell should have a specific gravity between 1.265 and 1.285 when measured at the standard reference temperature of 77°F (25°C).

Question 3

What is the primary purpose of a battery equalizing charge?

Accepted Answer

To balance cell voltages and reverse sulfation in flooded lead-acid batteries

Answer

An equalizing charge applies a controlled overcharge to balance cell voltages across a battery string and help reverse mild sulfation that accumulates during normal cycling.

Question 4

When two 12V, 100 Ah batteries are connected in series, what is the resulting voltage and capacity?

Accepted Answer

24V, 100 Ah

Answer

Series connections add voltages while keeping capacity the same, so two 12V 100 Ah batteries in series produce 24V at 100 Ah.

Question 5

Which type of starting motor is most commonly used on diesel generator sets due to its high torque at low speeds?

Accepted Answer

Series-wound DC motor

Answer

Series-wound DC motors produce maximum torque at startup and low speeds, making them ideal for engine cranking applications where high breakaway torque is required.

(EGSA) Electrical Generating Systems Association Certified Practice Test

(EGSA) Electrical Generating Systems Association Certified Practice Test

EGSA Battery and Starting Systems