2. Battery Safety
• WEAR SAFETY GLASSES!
• Avoid any arcing or open flames near a
battery
Hydrogen was here
3. Battery Safety (continued)
• WEAR SAFETY GLASSES!
• Do not allow battery acid to come in
contact with skin, eyes, or clothing
• Observe polarity when making
connections to the battery
• Always disconnect the negative cable
first
• Always connect the negative cable last
4. Battery Safety (continued)
• WEAR SAFETY GLASSES!
• Follow manufacturer’s recommendations
when charging
• Add only distilled water when low
• Do not wear jewelry when servicing a
battery
5. Battery Safety (continued)
• WEAR SAFETY GLASSES!
• Never lay tools on a battery
• Always wear safety glasses when
servicing a battery
• If frozen, allow the electrolyte to defrost
before doing any service
6. Common Automotive Batteries
• Lead Acid Battery
– Most Common
• Recombination / Gel-Cell Battery
– Popular replacement
– Used when battery is located in cab
• Nickel Metal Hydride (NiMH)
– Used in Hybrid vehicles
8. Recombination/ Gel Cell Batteries
• Uses gel instead of liquid
electrolyte
• Can be installed in any
position
• Is corrosion free and has
very low maintenance
• Can last up to four times
longer than conventional
batteries
• Can withstand deep
cycling without damage
• Can be rated at over 800
cold cranking amperes
10. Functions of a Battery
• Operates the electrical devices for the
engine during cranking and starting
• Supplies electrical power for the vehicle
accessories when the engine is not
running
• Furnishes current for a limited time
whenever electrical demands exceed
charging system output
11. Functions of a Battery
(continued)
• Acts as a voltage stabilizer for the entire
automotive electrical system
• Stores energy for extended periods of time
12. Batteries
• Most batteries have six 2.1 volt cells
• Cells are “wired” in series like a flash light
• 2.1 volts X 6 cells =12.6 volts
• Remember…12.6 volts equals
Fully Charged Battery!
13. Parts of a Battery
• Positive plates
• Negative plates
• Separators
• Case
• Plate straps
• Electrolyte
• Terminals
14. The KISS Theory of How They
Work
• When the Battery is fully charged:
You got a positive plate (lead peroxide that
wants electrons)
You got a negative plate (sponge lead that
has plenty of electrons to spare)
Both plates soak in a water/sulfuric acid
solution (that allow electrons to move)
15. The KISS Theory
• As the battery discharges, the:
– Lead peroxide turns to lead sulfate (neutral)
– Sponge lead turns to lead sulfate (neutral)
– Sulfuric acid turns to water (neutral)
16. The Kiss Theory
• As the battery charges (if all is well inside)
– The lead sulfate on the positive plates return
to lead peroxide
– The lead sulfate on the negative plates return
to lead peroxide and lead sponge
– The water returns to sulfuric acid
17. Battery Specific
Gravity Readings
• Fully charged: 1.265
• 75% charged: 1.225
• 50% charged: 1.190
• 25% charged: 1.155
• Discharged: 1.120 or
lower specific gravity
• Water = 1.000
Hydrometer
Refractometer
18. Maintenance -Free Batteries
• Calcium or
Cadmium added
to plates to
prevent gassing
• Plate design
different to lower
internal
resistance
19. Factors Related to Battery
Current Capacity
• The size of the cell plates
• The weight of the positive and negative
plate active material
• The weight of the sulfuric acid in the
electrolyte solution
20. Battery Ratings
• Ampere-hour rating
– Amount of steady current a fully charged
battery can supply for 20 hours at 80° F
• Leaving headlights on
• Cold cranking amps (CCA) rating
– Load in amperes a battery can deliver for 30
seconds at 0°F w/o dropping below 7.2 volts
• Oh Lord, I’m stuck in Lodi again…
21. Selecting the Correct Battery
• Factors that determine battery size
– Engine size, number of cylinders
• Need bigger battery for bigger engine
– Climatic conditions
• Need bigger battery for colder conditions
– Vehicle options
• Need bigger battery for more toys
• A general rule is 2 CCA per cubic inch
of engine displacement-minimum!!!
22. Types of Battery Terminals
• Post or top terminals
– Most common
• Side terminals
– When space is critical
• L-terminals
– Used by some imports
and motorcycles
23. Battery Cables
• They are normally 4 or 6 gauge wires
• The positive cable is usually red and the
negative cable is usually black
• The negative cable is attached to the engine
block and may have “Pig Tails” going to body
and frame.
• The negative cable may be made with no
insulation and may even be a braided type cable
24. Causes of Battery Failure
• Cracks in the case
• Overcharging
– Usually indicated by low electrolyte level
– Can cause plates to warp or disintegrate
• Vibration
– Active material will shed from the plates,
causing a shorted cell
• Sulfation
– Bridging of plates caused by storage in low
charge state
25. Battery Inspection Tips
• Check the case
for damage, dirt,
and corrosion
• Check the
electrolyte level,
color, and odor
• Check the
condition of the
cables
• Check for signs of
obvious neglect
• Check the battery
hold-down fixture
26. Jump Starting
• Use quality cables
• Always hook up dead car
first!
• Connect Pos “+” Cable
First
• Connect Neg “–” Cable
Last
• Run engine at fast idle to
charge dead battery
• Don’t let cars touch!
27. Circuit Protection
You will need these if you jump battery backwards!
• Fuses-One time protection
• Circuit Breakers-Resettable protection
• Fuse Links-Large load one time protection
30. Circuit Breakers
• Can be Add-on or
located in fuse block
• Rating is located on
top of circuit breaker
• Most are self resetting
31. Fuse Links
• Fuse links rated by
wire gauge size
– Rule of Thumb -
Go down 4 wire sizes
from the circuit you are
protecting.
• Check with DVOM
• Tug on link to see if it
stretches
35. Starter Current Flow
• Battery to starter 12v all the time
• Ignition Switch
– safety switch (clutch or Pernandul PNDL switch)
• Starter solenoid
–Solenoid to starter
38. Electromagnetic Principles
• Voltage is be produced when motion
occurs between a wire and a magnetic
field
• The amount of voltage is affected by:
– Speed that wire passes through the
magnetic field
– Strength of the magnetic field
– Number of wires passing through
39. Charging Systems
• Used to “Top off” and maintain battery
• Generate current to make up for high
electrical demands
• Normal charging system voltage range
must be 13.8v to 14.8v
40. Common System Loads
• Air Conditioner 20 amps
• High Beams 13-15 amps
• Rear window Defroster 30 amps
• Audio Power Amps 10-70 amps
• Alternator output should be about 50% greater
than the load to keep up battery
• Normal load at 70 amps…you need a 100amp
alternator.
41. Charging System Components
• Battery
• AC generator with
diode rectifier to
convert to DC volts
• Drive belt
• Voltage regulator
• Charge indicator
lamp or gauge
• Ignition switch
• Cables and wiring
harness
• Starter relay
(some systems)
• Fusible link (some
systems)
