AS113 - Lecture - Lead Acid Batteries

Question 1

A device of two or more cells that changes chemical energy into electrical energy.

Answer 1

Battery

Question 2

There are two Categories of battery

PG. 3-53 & 10-90

Answer 2

Primary Cell

Secondary Cell

Question 3

Compact, light weight.

The active elements in this battery become exhausted and cannot be restored.

Answer 3

Primary Cell or Dry Cell

Question 4

There are three Types of Primary Cells

Answer 4

1. Carbon-Zinc cell
2. Alkaline cells
3. Mercury Cells

Question 5

Electrons flow from zinc to carbon rod.

Produces 1.5 vdc regardless of size.

Size of cell will determine current.

Ammonium chloride-electrolyte .

Answer 5

Carbon-Zinc cell

Question 6

Longer life and less expensive.

Zinc rod, potassium hydroxide electrolyte solution.

Potassium hydroxide has a lower resistance than ammonium chloride of carbon-zinc cells.

Built differently.

Answer 6

Alkaline cells

Question 7

Use for hearing aids, cameras, etc..

High capacity.

Mercuric oxide (positive).

Potassium hydroxide (negative)-electrolyte.

Answer 7

Mercury Cells

Question 8

Takes electrical energy and stores it chemically.

When called upon it converts chemical energy into electrical energy.

Answer 8

Secondary Cells

Question 9

Typical battery consists of 6 or 12 cells.

Each cell produces 2.1 volts.

6 cells- 12volt battery.

12 cells- 24 volt battery.

Answer 9

Lead acid battery

Question 10

Battery most commonly used on aircraft

Answer 10

Lead acid battery

Question 11

Grid of lead and antimony filled with lead peroxide.

Answer 11

Positive Plates

Question 12

Similar grid but it is filled with Spongy lead.

One extra negative plate

Answer 12

Negative Plates

Question 13

Plates do not go all the way to the bottom because.

Answer 13

This allows for sediment to collect

Question 14

Separates plates and allows electrolyte (sulfuric acid and water) to keep in contact with the active material on plates.

Answer 14

Porous Separator

Question 15

Battery Case is made of; (smaller aircraft)

Answer 15

Hard plastic (previously hard rubber)

Question 16

Close cell openings

Have lead weights to prevent electrolyte from escaping at unusual flight attitudes.

Answer 16

Vented screw-in type Caps

Question 17

Battery case for Large aircraft is made of?

Answer 17

Steel case (larger aircraft)-for shielding and mechanical protection.

Question 18

Electrons flow from negative to positive plates.

Positive Ions form on negative plates

which attracts negative sulfate ions from the sulfuric acid.

Answer 18

Discharge

Question 19

This reaction causes lead sulfate to form on both the positive and negative plates.

As the sulfate ions are attracted by the plates the electrolyte becomes diluted.

Water then forms.

At this discharged state the battery is more susceptible to freezing.

Answer 19

Discharge

Question 20

Electrons drawn from positive plates and force on negative plates.

Electrons drive lead sulfate back into the electrolyte.

This makes the electrolyte sulfuric acid again.

Hydrogen gas is created and released.

Answer 20

Charge

Question 21

“Condition of Charge”

Open circuit voltage (OCV)

Answer 21

2.1 vdc per cell

OCV does not reflect the state of battery charge.

Question 22

1.275-1.300 fully charged

@ 80 degrees F

1.150 battery discharged

Answer 22

Specific Gravity

Question 23

Below ______________________,
there is not enough chemical
strength in the electrolyte to
convert the active material into
lead sulfate.

Answer 23

1.150 specific gravity

Question 24

uses a calibrated float

more dense the liquid higher the specific gravity

more buoyant the hydrometer more dense the liquid

Answer 24

Hydrometer

Question 25

Electrolyte is ____ dense at ______ temperatures, and more dense at lower temperatures.

Answer 25

less higher

Question 26

Active material converts into lead sulfate which increases the battery’s internal resistance when a.

Answer 26

A load is placed on the battery

Question 27

The ability to produce a given amount of current for a specified time.

Answer 27

Capacity

Question 28

______ is measured in ampere-hours

Answer 28

Capacity

Question 29

Capacity is affected by four things

Answer 29

1. Amount of active material. 2. The plate area. 3. Quantity of electrolyte. 4. Temperature:

Question 30

Cold temperature decreases _______.

Answer 30

Capacity

Question 31

50 F fully charged battery may provide power for ____ hours. 0 F same battery supplies power for _____ hour.

Answer 31

5hr 1hr

Question 32

Standard rating used to specify the capacity of a battery.

Answer 32

Five Hour Discharge:

Question 33

5 amps for 5hours capacity = ____ampere-hours

Answer 33

25

Question 34

Capacity will ______ when discharged at a higher rate.

Answer 34

decrease

Question 35

This is due to heat, sulfation of plates and the tendency of the electrolyte to become diluted immediately around the plates.

Answer 35

Capacity decreasing when discharged at a higher rate.

Question 36

Cell Test: With load on the battery test cells. All cells should be within ___ volts of each other.

Answer 36

.05

Question 37

Cell Test: Verify electrolyte level is ___. Apply a heavy load for ___ sec. by cranking engine w/starter and ign. off. Turn on taxi lights or landing lights, enough to draw ___ amps. While load current is ________, measure voltage at each cell.

Answer 37

3 10 flowing

Question 38

A good battery will not go below _____ and all cells should be within _____ of each other.

Answer 38

1.95v .05v

Question 39

In a discharge condition. If any cell is higher than 1.95v with more than .05v difference between any cell, then a cell is _______.

Answer 39

defective

Question 40

How to service and charge a battery

Answer 40

Keep terminals clean, connections tight with no corrosion. Clean corrosion with brush and baking soda. Coat terminals – Use manufacturer’s recommended grease. Insure correct level of electrolyte. Add only distilled or de-mineralized water.

Question 41

Do not get the baking soda in battery.

Answer 41

It will neutralize the electrolyte.

Question 42

How do you dilute acid

Answer 42

Pour acid into the water Never pour water into acid

Question 43

Pouring water into acid will cause a severe ______ reaction with acid

Answer 43

exothermic

Question 44

If acid gets into your eyes, flush with _______.

Answer 44

water

Question 45

Never mix automotive and aircraft _______

Answer 45

electrolyte

Question 46

NEVER _____ THE TERMINALS OF A BATTERY.

Answer 46

SHORT

Question 47

_________ SHOULD BE USED WHEN TRANSPORTING BATTERIES.

Answer 47

CARRYING STRAPS

Question 48

PROTECTIVE CLOTHING, SUCH AS; SHOULD BE WORN WHEN WORKING WITH BATTERIES.

Answer 48

RUBBER APRON RUBBER GLOVES FACE SHIELD

Question 49

__________, ELECTRIC SPARKS, OR OPEN FLAMES SHOULD BE PERMITTED NEAR CHARGING BATTERIES.

Answer 49

NO SMOKING

Question 50

CARE SHOULD BE TAKEN TO PREVENT __________ OF THE ELECTROLYTE

Answer 50

SPILLING

Question 51

A mixture of hydrogen and air can be dangerously _______. No smoking, electric sparks, or open flames should be permitted near charging batteries.

Answer 51

Explosive

Question 52

Charging source must be ____ than open circuit voltage (OCV)

Answer 52

greater

Question 53

Batteries are charged by either ________ or _________

Answer 53

Constant Current or Constant Voltage Charging

Question 54

Most effective Always follow MFG’s recommendations Multiple batteries - connect in series when charging

Answer 54

Constant Current Charging:

Question 55

Aircraft charges batteries by constant voltage. Shop chargers boost or jump battery- not airworthy.

Answer 55

Constant Voltage Charging:

Question 56

(8083) Passing direct current through the battery in a direction opposite to that of the discharge current _____ charge a storage battery. Because the internal resistance (IR) in the battery, the voltage of the external charging source must be ______ than the open circuit voltage.

Answer 56

may greater

Question 57

When Installing the Battery _______ terminal gets connected first. _______ terminal last (this “arms” the battery).

Answer 57

Positive Negative

Question 58

When removing the Battery: _______ terminal must be disconnected first (this “disarms” the battery). _______ terminal last.

Answer 58

Negative Positive

Question 59

Keep wrenches, screwdrivers, jewelry, etc. from making unwanted contact with the terminals! True/Flase

Answer 59

True

Question 60

Parallel-Series Battery Connections: Connecting batteries in parallel increases ______ (capacity), but not ______.

Answer 60

amps voltage

Question 61

Connecting batteries in series increases _______, but not _______.

Answer 61

voltage capacity

Question 62

Vents-vent fumes from inside the battery box.

Answer 62

Battery Box

Question 63

Sump jar-contains _________ ______ moistened with sodium bicarbonate and water.

Answer 63

absorbent pads

Question 64

A ______ is a device that transforms chemical energy into electrical energy.

Answer 64

CELL

Question 65

The cell has three parts;

Answer 65

the electrodes, the electrolyte, and the container.

Question 66

There are two basic cells:

Answer 66

primary and secondary

Question 67

________are the current conductors of the cell.

Answer 67

ELECTRODES

Question 68

_______is the solution that acts upon the electrodes.

Answer 68

THE ELECTROLYTE

Question 69

_________holds the electrolyte and provides a means of mounting the electrodes.

Answer 69

THE CONTAINER

Question 70

is a cell in which the chemical action finally destroys one of the electrodes, usually the negative. The primary cell cannot be recharged.

Answer 70

THE PRIMARY CELL

Question 71

_______is a cell in which the chemical action alters the electrodes and electrolyte.

Answer 71

THE SECONDARY CELL

Question 72

The electrodes and electrolyte can be restored to their original condition by ________ the cell.

Answer 72

recharging

Question 73

_______ is the process of converting chemical energy into electrical energy.

Answer 73

ELECTROCHEMICAL ACTION

Question 74

________ is the positive electrode of a cell.

Answer 74

THE ANODE