Batteries

Question 1

How many volts is a batterie and what frequency?

Answer 1

24V DC and 400 Hz

Question 2

What does transformer rectifier unit (TRU) do?

Answer 2

Changes AC to DC

Question 3

How many IDGs are there?

Answer 3

1 on each engine

Question 4

Name some DC sources?

Answer 4

-DC battery
-DC power source (external)
-DC generator

Question 5

What are the 2 main battery uses?

Answer 5

-For emergency power
-APU starter motor power for APU start

Question 6

Why do we do battery venting?

Answer 6

To prevent buildup of fumes

Question 7

How do we make sure battery venting doesn’t damage the aircraft?

Answer 7

Acid trap
One way valve
Rubber tube

Question 8

How are battery connectors secured?

Answer 8

Using copper lock wire

Question 9

What’s a battery trays job?

Answer 9

To secure batteries and collect spilt electrolyte

Question 10

What are the two battery types?

Answer 10

Nickel cadmium
Lead acid

Question 11

How often are batteries checked and for what?

Answer 11

Every 2000 use hours for:
-storage capability
-electrolyte condition

Question 12

What are the battery line maintennence cautions?

Answer 12

-never overheat because of too many APU start attempts
-don’t discharge battery below 22V or weakest cell can invert polarity
-charge level should be checked and kept at fully charged

Question 13

What battery is most likely to have thermal runaway?

Answer 13

Nickel cadmium

Question 14

Name 2 causes of thermal run away?

Answer 14

-unbalanced cells
-loose connections
-internal shorting
-reversed cells
-separator damage

Question 15

What are the two battery charging methods?

Answer 15

-Constant voltage method
-Constant current method

Question 16

What is the constant voltage method used for?

Answer 16

Lead acid

Question 17

What is the constant current method used for and what’s the risk?

Answer 17

For nickel cadmium and risk of overcharging

Question 18

What percentage should batteries be?

Answer 18

80% capacity

Question 19

How long must a battery be able to provide essential power for?

Answer 19

30 mins

Question 20

When does a battery disconnect from charge?

Answer 20

At high temperature

Question 21

Is a battery in flight continuous or intermittent ?

Answer 21

Continuous charging

Question 22

What do you disconnect first in battery charging?

Answer 22

Negative connection first and connects last on install