Ch14 Commercial Vehicle Batteries

1. Battery electrolyte is a mixture of water and: A. Sulfate B. Lead sulfate C. Sulfuric acid D. Ammonia

1. C. Sulfuric acid, P326

7. Technician A says battery plates are made of two different compositions of lead that are fabricated from paste and bonded to lead-alloy grids. Technician B says the negative plate uses lead peroxide (PbO2) and the positive plate uses lead (Pb). Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

7. A., p330

8. Technician A says both soft and hard sulfate can be driven from the plates, bringing the battery back into service. Technician B says leaving a battery in a state of discharge for a long time hardens and prevents sulfate from being driven from the plates. Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

8. B., p332

9. Technician A says during charging and discharging, water in the electrolyte is broken apart into its constituent hydrogen and oxygen thru a process called electrolysis. Technician B says if battery electrolyte is too low, the plates dry out, and the increased acid concentration of electrolyte permanently damages the grids. Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

9. C., p332

Starting, Lighting, and Ignition (SLI) Battery

A battery designed for one, short-duration, deep discharge of up to 50% depth of discharge (DOD) during engine cranking.

Primary battery

A battery in which chemical reactions are not reversible and the battery cannot be recharged.

Absorbed Glass Mat (AGM) battery

A battery in which electrolyte is absorbed n a fine glass mat that prevents the solution from sloshing or separation into layers of heavier acid and water.

Sealed lead-acid (SLA) battery

A battery that does not have liquid electrolyte nor requires the addition of water; also called a valve-regulated lead-acid battery (VRLA) or recombinant battery.

Deep-cycle battery

A battery used to deliver a lower, steady level of power for a much longer time.

Galvanic reaction

A chemical reaction that produces electricity when two dissimilar metals are placed in an electrolyte.

Sulfation

A chemical reaction that results in the soft sulfate turning to a hardened crystalline form that cannot be driven from the plates in the battery.

Flooded lead-acid battery

A lead-acid battery in which the plates are immersed in a water-acid electrolyte solution.

Amp-hour

A measure of how much amperage a battery can continually supply over a 20-hour period before he battery voltage falling below 10.5 volts.

Cold-cranking amps (CCA)

A measurement of the load, in amps, that a battery can deliver for 30 seconds while maintaining a voltage of 1.2 volts per cel (7.2 volts for a 12-volt battery) or higher at 32 degrees F.

Secondary battery

A rechargeable battery

Traction battery

A rechargeable battery used for propulsion in hybrid electric vehicles.

Starting, lighting, and ignition batteries (SLI) are designed for

A single short-duration deep discharge during engine cranking. Deep-cycle batteries provide lower amperage current continually for electrical devices and accessories.

Gassing

A situation that occurs when overcharging or rapid charging causes some gas to escape from the battery.

Valve-regulated lead-acid (VRLA) battery

A type of sealed lead-acid battery used in heavy-duty equipment; it does not require the addition of water; also called a sealed lead-acid battery (SLA) or recombinant battery.

6. Technician A says the battery case is usually made of polypropylene with ribbing and irregular features to reduce the amount of current leakage across the battery surface. Technician B says ribbing and irregular features on the outside of the case add to the strength of the battery and make it sturdier. Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

A. , p327

5. Which of the following procedures can best neutralize battery acid? A. Applying baking soda to the acid B. Applying. Baking powder to the acid C. Power washing the acid D. Diluting the acid with kerosene or diesel fuel

A. Applying baking soda to the acid, ???

2. What is the positive plate material made of in a discharged battery? A. Lead peroxide B. Lead sulfate C. Sponge lead D. Hydrogen dioxide

A. Lead peroxide, p324, 330

1. While observing a truck with an alternator cable that is burnt and has many fuses and fusible links blown, Technician A says the battery was connected in reverse polarity. Technician B says the batteries were likely deeply discharged and charged at a high current rate. Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

A. Tech A, p332

Electrolyte

An electrically conductive solution.

Hydrometer

An instrument used to measure the specific gravity of liquids.

Through a galvanic reaction, electricity is produced when two dissimilar metals

Are placed in an electrolyte.

3. Consider three 12-volt 500 CCA batteries connected in series. what is the available voltage and amperage of the combined batteries? A. 12 volts 1,500 amps B. 36 volts, 500 amps C. 12 volts, 500 amps D. 24 volts, 1,000 amps

B. 36 volts 500 amps, 3 x 12 = 36

5. Technician A says lead-acid battery electrolyte is a mixture of 64% sulfuric acid and 36% water. Technician B says sulfuric acid has a specific gravity of 1.835, which means it is much heavier than water. . Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

B. Tech B, p326

10. Which method of plate construction is used in a SLI-type battery? A. Cells with many thin, highly resistive plates B. Cells with thicker, low-resistance plates C. Cells with thinner, low-resistance plates D. Cells with thicker, high-resistance plates

C. , p325

9. What battery measurement is performed when measuring the electrolyte's specific gravity? A. The open-circuit voltage B. The battery capacity C. The battery's state of charge D. The battery's potential cranking amperage.

C. , p326

6. The two gases produced by a battery during charging and discharging are: A. Carbon dioxide and hydrogen B. Carbon monoxide and hydrogen C. Oxygen and hydrogen D. Nitrogen and hydrogen

C. , p332

7. A maintenance-free or VRLA battery contains almost none of the following alloy in its plate grid material: A. Calcium B. Barium C. Antimony D. Strontium

C. , p332

8. A battery that is left in a discharged state for long period of time becomes: A. Cycled B. Shorted C. Sulfated D. Overheated

C. , p332

4. Which of the following is the open-circuit voltage (when no electrical loads are connected) of a battery between 50% to 75% charge? A. 12 volts B. 12.6 volts C. 7.3 volts D. 12.4 volts

C. 7.3 volts, ???

4. Technician A says the primary difference between deep-cycle batteries and SLI is the thickness of the plates. Technician B says deeply discharging SLI batteries dramatically shortens their service life. Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

C. Both, p325

10. Technician A says hydrogen and oxygen gasses produced when charging and discharging AGM batteries can cause an explosion if a spark is produced at the battery terminal when boosting. Technician B says the AGM battery can deliver more cranking amperage and absorb more charging current than conventional lead-acid batteries. Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

C. Both, p333

2. Technician A says a spiral cell (Optima battery) is not considered a sealed lead-acid (SLA) battery. Technician B says an absorbed glass mat (AGM) battery is not considered a SLA battery. Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

D. Neither, p323

3. Technician A says a fully charged 12-volt battery is 12 volts. Technician B says a battery with a 50%^ state of charge has close to 6 volts when no electrical loads are connected. Who is correct? A. Technician A B. Technician B C. Both Technician A and Technician B D. Neither Technician A nor Technician B

D. Neither, p324

A starting-lighting-ignition battery can supply very high

Discharge currents while maintaining a high voltage, which is useful when cold starting. A lead-acid battery gives high power output for its compact size, and it is rechargeable.

Sulfation takes place when a battery is left in a

Discharged or only partially charged condition long enough for sulfate to permanently bond to the plates.

Sulfate originates from the sulfuric acid in electrolytes that enters the plates when the battery is

Discharging. Sulfate is originally soft but becomes a hardened crystal over time.

Batteries have traditionally been used in

Heavy vehicles to provide starting current and operate electrical accessories if the engine is not running.

Batteries can be configured into battery banks in cases where

Higher cranking amperage or higher-voltage batteries are required.

During charging and discharging, batteries produce

Hydrogen and oxygen gas caused by the breakdown of water thru a process called hydrolysis. These gases require venting and are an explosion hazard.

Lead-acid batteries can be manufactured with electrolyte. Dry batteries can be stored

On the shelf for extended periods without the fear of sulfate. Dry batteries are lighter to transport.

Lead-acid batteries deliver high rates of current with a higher tolerance for physical and electrical abuse compared to

Other battery technology. These batteries hold a charge well and when stored dry - without electrolyte - the shelf life is indefinite.

Compare energy densities.

P338,

Give Lithium-Ion Battery Advantages

P339,

Give Lithium-Ion Battery Advantages (continued)

P340,

Show graph displaying number of charge/discharge cycles for types of batteries.

P340,

Give construction detail of an LFP battery

P342,

Give Advantages for Valve-Regulated Lead-Acid Batteries (VRLA)

P343,

Show how batteries develop unequal resistances with use.

P350,

Secondary batteries operate using the

Principles of galvanic reaction and are the most practical for use in commercial vehicle applications.

There are two types of batteries. Primary batteries cannot be

Recharged; secondary batteries are rechargeable.

Electrical capacity

The amount of electrical current a lead-acid battery can supply measured in cranking amps or cold cranking amp capacity.

Reserve capacity

The time, in minutes, that a new, fully charged battery at 80 degrees F supplies a constant load of 25 amps without its voltage dropping below 10.5 volts for a 12-volt battery.

Electrolysis

The use of electricity to break down water into hydrogen and oxygen gases.

Battery temperature plays an important role in the performance of a battery and lead-acid batteries have ideal operating temperature range. A battery's internal resistance depends on the

Types of materials used to make the plates and the chemical composition of the electrolyte. A battery's internal resistance determines how quickly a battery can be charged or discharged.

Parasitic draw

Unwanted drain on the vehicle battery when the vehicle is off; also called key-off electrical load.

Key-off electrical loads

Unwanted drain on the vehicle battery when the vehicle is off; also called parasitic draw.

Batteries are classified by use, application, and chemistry used

Within the battery. Although lead-acid batteries are most prevalent, hybrid-drive vehicles also make use of nickel-metal hydride and lithium batteries.

Regardless of battery construction, all batteries have the same basic components:

case, terminals, plates, cell straps and electrolyte.