Batteries

A new, fully charged, battery will have

70% water, 30% acid (by volume), and a specific gravity of 1.300

What is a storage battery?

A battery with multiple secondary cells

When is a mercury battery useful?

When size and weight outweigh the costs

Is it possible to recharge a lead-acid battery many times before it deteriorates?

Yes

Carbon-zinc battery negative pole is made of....

Zinc

What tends to dissolve away as a carbon-zinc battery is dissipated?

Zinc electrode

What produces more current, an alkaline cell or a carbon-zinc battery?

Alkaline cell, although both produce the same voltage

What are lead acid batteries used in aircraft similar to?

Automobile batteries

Why. Are common batteries sealed in a steel jacket?

Because as a battery expands energy, it tends to leak

Carbon-zinc battery positive pole is made of....

Carbon

The common flashlight has a.....

Carbon rod and an electrolyte made of ammonium chloride, manganese dioxide, and granulated carbon and in a zinc canister

A battery converts.....

Chemical energy into electrical energy

When a lead-acid battery discharges, what kind of energy does it convert?

Chemical into electrical

What does an alkaline cell use as an electrolyte?

Potassium hydroxide

The common flashlight uses a......

Primary cell

During battery discharge, the acid content is

decreasing and the water content is increasing

The state of charge is indicated by the

density of the electrolyte measured with a hydrometer

how should vent caps be left during charging?

loosened but left in place

The endplate in each cell is a

negative plate

Between a nickel-cadmium battery and a lead-acid battery, what has higher initial costs?

nickel-cadmium

What type of brush should be used when cleaning a battery?

non-conductive type brush

What is the electrolyte in a Ni-Cad battery?

30% potassium hydroxide and distilled water

How many amperes does a 35 amp hour battery produce for one hour?

35

What is the standard discharge rate for an aircraft battery?

5 hours

How many amperes does a 25 amp hour battery produce for a 1/2 hour?

50

A battery in a state of charge less than ___ needs immediate recharging

50%

A 12 volt battery has how many cells?

6

How many volts per cell does a freshly charged battery have?

2.2

Name two common high discharge rates for an aircraft battery

20 minute and 5 minute

What is the freezing point of a fully charged lead-acid battery?

-90°F

The range markings of a battery hydrometer are

1.100 to 1.300

A specific gravity reading between ___ indicates a low state of charge

1.200 and 1.240

A specific gravity reading between ___ indicates a medium state of charge

1.240 and 1.275

When charged, a lead-acid battery electrolyte density is

1.275 - 1.300

A specific gravity reading between ___ indicates a high state of charge

1.275 and 1.300

You are reading a hydrometer at 40°F and your actual reading is 1.295, what is your actual specific gravity?

1.279

You are reading a hydrometer at 38°C and your actual reading is 1.285, what is your actual specific gravity?

1.293

How many volts per cell in a carbon-zinc battery?

1.5 volts

A 24 volt battery has how many cells?

12

How many volts does a freshly charged battery drop to due to internal resistance?

2.0

When recharging a battery, what is changed and stored?

Electrical energy supplied to the battery is changed to chemical energy

The framework of a lead-acid battery is made of.....

Lead and antimony

In a lead-acid battery, what is the positive plate made of?

Lead peroxide

How does current flow in a carbon-zinc battery?

Negative to positive

Primary cells

Non-rechargeable cells

Secondary cells

Rechargeable cells

Why cant a carbon-zinc battery be recharged?

Recharging cannot replace the zinc

What type of battery cells are used in aircraft?

Secondary

Which can be recharged, a primary cell or a secondary cell?

Secondary cell

Cells

Smaller power producing units that make up a battery

In a lead-acid battery, what is the negative plate made of?

Spongy lead

The active material attached to the framework is.....

Spongy lead and lead peroxide

In a lead-acid battery, what is the electrolyte made of?

Sulfuric acid and water

In a carbon-zinc battery, what are hydrogen ions attracted to?

The carbon rod

What may batteries provide in the event of a primary source failure?

The only source of power or reserve/standby

What does the amount of current in a carbon-zinc battery depend on?

The size of the cell

Mercury pellet

Used by a mercury battery in place of a carbon rod as an electrode

A Ni-Cad battery state of charge cannot be determined by what?

a hydrometer

What is a Ni-Cad battery positive plate made of?

a porous plaque on which nickel-hydroxide has been deposited

What is a Ni-Cad battery negative plate made of?

a porous plaque with cadmium-hydroxide deposits

The state of charge of a lead-acid battery depends on the condition of the

active material, primarily the plates

Connecting batteries in parallel increases the

ampere-hour capacity

What is the capacity of a battery rated in?

ampere-hours

What are batteries frequently used as in an aircraft?

as a dc power source

When should you do a hydrometer reading?

before adding water

The best range for reading a battery hydrometer is when the temperature is

between 70°F and 90°F degrees F

What can be used to clean lead-acid batteries?

bicarbonate soda, commonly known as baking soda and water

The cell separators are porous with vertical ribs that allow the electrolyte to

circulate freely and sediment to settle to the bottom.

Name two methods of charging a lead-acid battery

constant-current and constant-voltage

What should a lead-acid electrolyte level be at?

depending on the battery manufacturer, slightly above the top of the plates or up to the bottom of a ring in the cell filler neck

A lead-acid battery that is heavily discharged is

difficult to recharge due to high resistance caused by sulfate coating

What would you add to the electrolyte if it is found to be low?

distilled water

If baking soda is allowed into the electrolyte, what would happen?

it would neutralize the electrolyte

The negative plate of a lead-acid battery is coated with:

lead (Pb)

The positive plate of a lead-acid battery is coated with:

lead peroxide (PbO2)

A nearly totally discharged lead-acid battery is of

little use due to high internal resistance of the sulfate coating on the plates.

When charging a lead-acid battery, how is DC current passed?

opposite that of discharge current

When charging a lead-acid battery....

oxygen and hydrogen gases are produced in an explosive mixture

Hydrometer tests are made how often on aircraft batteries?

periodically

What is the purpose of the "vent plug"?

permits gasses to escape with the minimum of leakage, regardless of the aircraft's attitude

What keeps the positive and negative plate from touching and shorting the cell?

porous separators

What should you check for in battery vent lines?

proper attachment, cuts, kinks, or blockages

When charging the water content of the electrolyte is

reduced

What will a lead-acid battery do if it isnt kept clean?

self-discharge

How do you store Ni-Cad and lead-acid batteries?

separately

what are the advantages of a Ni-Cad battery?

short recharge time, excellent reliability, and good starting capability

The electrolyte density is measured as

specific gravity

A hydrometer measures the

specific gravity of a liquid

The liquid electrolyte is made of:

sulfuric acid (H2SO4) and water (H20)

Hydrometer readings may vary from actual specific gravity due to changes in

temperature

The non-spill vent cap on top of each cell is for:

testing the electrolyte and servicing the battery

The voltage of a lead-acid battery is dependant on

the cells that are connected in series to form a battery

The more dense the electrolyte

the higher the float in the hydrometer will be

During charging the lead sulfate is removed from the plates and

the sulfuric acid is again formed

During discharge, the lead sulfate on the plate becomes too

thick to allow a weakened electrolyte to reach the active material

The ampere-hour capacity depends on

total effective plate area

Connecting batteries in series increases the

total voltage

When assembled, a lead-acid battery positive plate is placed between:

two negative plates

What should you do if electrolyte from the lead-acid battery makes contact with your skin?

wash the area thoroughly with water and then apply baking soda

Can Ni-Cad and lead-acid batteries be interchanged?

yes