General - AM.I.A.K15 - Aircraft batteries

Question 1

What is meant by the capacity rating of a lead acid battery?

Answer 1

The number of hours a battery can supply a given current flow

Question 2

What electrolyte is used in a lead acid battery?

Answer 2

A mixture of sulfuric acid and water

Question 3

Does the specific gravity of the electrolyte in a lead acid battery increase or decrease as the battery becomes discharged?

Answer 3

It decreases

Question 4

What is the specific gravity of a fully charged lead acid battery?

Answer 4

Between 1.275 and 1.300

Question 5

How many cells are there in a 24 volt lead acid battery?

Answer 5

12

Question 6

What is the range of temperatures of the electrolyte in a lead acid battery that does not require a correction when measuring its specific gravity?

Answer 6

Between 70 and 90 degrees Fahrenheit

Question 7

How do you treat a lead acid battery compartment to protect it from corrosion?

Answer 7

Paint it with an asphaltic (tar-based) paint or with a polyurethane enamel

Question 8

What is used to neutralise spilled electrolyte from a lead acid battery?

Answer 8

A solution of bicarbonate of soda and water

Question 9

How high should the electrolyte level be in a properly serivced lead acid battery?

Answer 9

Only up to the level of the indicator on the cell

Question 10

Why is the closed circuit voltage of a lead acid battery lower than its open circuit voltage?

Answer 10

Voltage is dropped across the internal resistance of the battery

Question 11

What gases are released when a lead acid battery is being charged?

Answer 11

Hydrogen and oxygen

Question 12

What is the electrolyte used in a nickel cadmium battery?

Answer 12

Potassium hydroxide and water

Question 13

What is a hydrometer not used to measure the state of charge of a nickel cadmium battery?

Answer 13

The electrolyte of a nickel-cadmium battery does not enter into the chemical changes that occur when the battery is charged or discharged. Its specific gravity does not change appreciably

Question 14

Is the electrolyte level of a nickel cadmium battery lowest when the battery is fully charged or fully discharged?

Answer 14

Fully discharged

Question 15

What is the result of cell imbalance in a nickel-cadmium battery?

Answer 15

The low internal resistance allows current to flow between the unbalanced cells and generate heat

Question 16

What is a thermal runaway?

Answer 16

The large current flow allowed by the low internal resistance causes the cells to produce more heat than than they can dissipate. The heat further lowers the internal resistance so more current can flow. This continues until the battery destroys itself

Question 17

How may thermal runaway be prevented?

Answer 17

By carefully monitoring the temperature of the cells and controlling the charging current to prevent and excess of current flowing into the battery

Question 18

How is it possible to know when a nickel cadmium battery is fully charged?

Answer 18

Completely discharge the battery and give it a constant current charge to 140% of its ampere hour capacity

Question 19

What is used to neutralise spilled electrolyte from a nickel cadmium battery?

Answer 19

A solution of boric acid and water