Aircraft Electrical Systems - 1 - 1

What is the composition of the electrolyte in a Ni-Cad battery?

- 30% to 35% potassium hydroxide - 65% to 70% water scale by weight, not a volume Lead Acid- scale by volume

Acid hazard

- Ph<2 (typically sulfuric acid) - corrosive material - burns to skin - burns to eyes - never open the battery caps with your face directly over the battery

Plating for all copper aircraft wiring

- Tin (lowest temp) <- most common - Silver (medium temp) - Nickel (highest temp) <- most expensive

The ampere-hour capacity of a lead-acid battery is determined by :

- amount of active material - area of the plates - amount of electrolyte - temperature

The capacity of a cell depends upon what ?

- area of plate - amount of active material - amount of electrolyte - temperature

Hydrogen gas

- by product of the battery's charging process - lighter than air - flammable in nature - explosive - can not taste or see the gas vapors - can smell the acid in the battery if it heats up

What are the methods used to charge nickel-cadmium batteries?

- constant current - constant voltage <- old style - pulse charging ( reflex charging, burp charging) <- modern style

Electrical hazard

- exposed terminals, even on disconnected batteries, present an electrical shock hazard

What gas is given off during battery charging?

- hydrogen gas - oxygen

For example of hazards associated with industrial batteries:

- hydrogen gas - sulfuric acid - shock - weight of the battery

By product of lead acid battery are :

- hydrogen gas - water - lead sulfate

Name the active materials on Lead-Acid battery plates.

- positive - lead peroxide ( metallic lead) - negative - lead dioxide ( sponge lead)

PPE requirements for electrolyte handling:

- safety glasses/ goggles - rubber gloves - face shield - chemical apron - boots

What is the electrolyte made of in a Lead-Acid battery?

- sulfuric acid - water

When neutralizing the alkaline , use the _________ and, ___________.

- vinegar - boric acid

The specific gravity of a fully charged lead-acid battery is approximately _____.

1.275

What is the nominal open-circuit voltage of a Ni-Cad cell?

1.55v - 1.80v

The open circuit voltage of a lead-acid battery is approximately ______ volts.

2.1

In a Lead-Acid battery, what is the nominal voltage of each cell?

2.1v

Mechanical strength of wire sizes less than # _____, do not use wire with less than _____ strands.

20, 19

Eyewash and drenching facilities are to be located as close to the point of exposure as possible of battery handling areas ( not to exceed _____ft)

25 ft NOTE- eyewash and drenching facilities are not required for non-vented batteries.

Hydrometer floats are calibrated to correctly indicate at what temperature?

26.7 C

___________ are electrical conductors in the cell where chemical reactions take place.

Electrodes

To prepare new electrolyte of a desired specific gravity, always pour the concentrated _____ slowly into the _____; Do NOT pour _____ into the _____. And always stir the ____ while adding small amounts of ____.

acid water water acid water acid

When mixing new electrolyte for a lead acid battery, always pour the _____ into the _____ slowly and stir to mix.

acid water

The ______ is the electrode where oxidation takes place.

anode

Spilled electrolyte from a lead-acid battery should be neutralized using a solution of ________ ______ and water.

baking soda

If water is added to any cell of a nickel-cadmium battery, the amount and location of the cell should be recorded in the _____ _____ _____.

battery service record

In a nickel- cadmium battery, we can recharge the battery by applying an electrical current from another source. But most batteries we use aren't rechargeable, why?

because doesn't have hydroxides

A primary cell _________(can or cannot) be recharged.

cannot

The _____ is the electrode where reduction takes place.

cathode The cathode receives the electrons given off at the anode and passes them along

Batteries are devices that convert _______ energy into ________ energy.

chemical electrical

Battery discharge- A system which converts _______ energy into _______ energy.

chemical, electrical

A battery is a device which changes ________ energy to _______ energy.

chemical. electrical

Which charging method is inefficient when it is desirable to ensure that a full recharge is given to the NiCad battery?

constant voltage

The capacity of a battery is its ability to produce a given amount of ______ (voltage or current ) for a specified time.

current

The constant ________ (current or voltage) charging method is the most effective method for charging aircraft batteries.

current

The _______ is the rate at which electrons pass through the cell, measured in ________.

current, amperes (A)

Under constant- current charging, the charging _____ level is controlled to maintain a steady charging _____ over the appropriate time period for the battery under charge.

current, voltage

Describe thermal runaway?

decreased the resistance, increased the current and makes raising temperature, so on until KA- BOOM

If the capacity of a nickel-cadmium battery is less than it should be, or if there is an indication that some of the cells are unbalanced, the battery should be _____ _____.

deep cycled

The specific gravity of the electrolyte in a nickel-cadmium battery _____ (does or does not) change as the state of charge of the battery changes.

does not

Battery charge- A system which converts _____ energy into ______ energy.

electrical, chemical

The Alkaline battery have the same voltage, because they're all base one the same __________ _____.

electrochemical cell

A battery is a group of __________ ______.

electrochemical cells

The solution is called _______, which causes a chemical reaction that produces electrons.

electrolyte

The electrolyte level of a nickel-cadmium battery is _____ (highest or lowest) immediately after the battery charge is completed.

highest

The solid ________ are sticky, which make battery rechargeable.

hydroxides ,which cling to the inside of the battery, and remain in place. ( The cathode consists of Ni ions in a NiO paste which are transformed into nickel hydroxide)

Consider covering battery terminals and connectors if possible with an _________ _______/ ______ before overhead inspections or repairs.

insulating blanket/ cloth

A 9v battery does not have the same voltage as "C" cell, why?

internally, the battery has 6 individual 1.5v cells connected together. battery have multiple cell, but the cell is just cell, just one.

What are the properties of some other typical batteries, which is not able to recharge?

it's one direction

The Lead Acid Battery is made up of ________ ______ with 35% __________ ______ and 65% _______ ________.

lead oxide, sulfuric acid, water solution

The active material on the positive plate of a fully charged lead-acid battery is _____ _____.

lead peroxide

The cathode ( + ) is made of metallic lead ( _______ _____), and the anode ( - ) is made of lead dioxide (___________ ______).

lead peroxide spongy lead

When a lead-acid battery is discharged, the active material on both positive and negative plates is converted to _____ _____.

lead sulfate

What is the density of lead-acid and Ni-cad, during the charging and discharging.

lead- acid -> change Ni-cad -> not change ( unable to determine the charging)

The most commonly used storage battery in light aircraft is the _______ battery.

lead-acid

The five-minute discharge rate of a lead-acid battery gives _______(more or less) ampere-hours than the five-hour rate?

less

During the service of a nickel-cadmium battery, the electrical leakage between the cells and the case should be checked using a _____.

milliammeter

When removing a battery from an aircraft, you should remove the _________ (positive or negative) lead first.

negative

When a load is connected across the cell, and current flows, electrons leave the ________ electrode and enter the _______ electrode. (discharging)

negative, positive

Both the positive and negative plates of a nickel-cadmium cell are made of powered nickel plaque, fused to a nickel screen. 1. The positive plates are impregnated with _____ hydroxide. 2. The negative plates are impregnated with _____ hydroxide.

nickel cadmium

Use _____ ______ containers to handle liquid.

non- metallic

Use of a circuit breaker as a switch is _____ recommended.

not

When installing a battery in an aircraft, you should connect the ________( positive or negative) lead first.

positive

Cell element

positive plate group separator negative plate group

The White powder that forms on the top of a nickel-cadmium battery that has been in service is __________ _____ _____ _____.

potassium carbonate

The electrolyte for a nickel-cadmium battery is _____ _____ and water.

potassium hydroxide

When acid has been splashed on clothing, a saturated solution of ________ should be applied.

sodium bicarbonate = baking soda

The active material on the negative plate of a fully charged lead-acid battery is _____ _____.

spongy lead

Do not attempt to _____ a battery if it slides out of equipment.

stop

Lead-acid batteries are referred to as "_________ _________" because this charge- discharge cycle is so reliable.

storage batteries

The electrolyte of a lead-acid battery is made up of _____ _____ and water.

sulfuric acid

Nickel-cadmium battery installations are required to have _____ monitoring equipment.

temperature

Batteries should never be lifted by the ________ _______.

terminal post

When jumping a vehicle battery, make certain that the vehicles are not touching and both ignition switches are _____________________.

turned to the OFF position

Ensure battery area _______ is operating prior to working on.

ventilation

High charging currents in nickel-cadmium batteries may cause a breakdown of the cellophane-like cell separator material, resulting in a condition known as _____ or _____.

vicious cycling, thermal runaway

Use an acidic solution such as _____ or ______ ______ for cleaning Ni-Cd spills.

vinegar boric acid

A nickel-cadmium battery can maintain a nearly constant ______ (voltage or current) until it is almost totally discharged.

voltage

The generating system in an aircraft utilizes the constant _______ (current or voltage) method to charge a battery.

voltage

The ______ of the whole cell is the electrical energy that it gives off, measured in _______.

voltage, volts (V)

Circuit breakers are designed as circuit protection for the ______, not for protection of black boxes or components..

wire