Chapter 11 what is a battery
Battery Council International (BCI)and Society of automotive engineering (SAE) establish:
Capacity ratings
Basic components of a battery:
Case, terminals, plates, electrolyte, size type, construction for applications
Specific gravity of electrolyte changes during:
Charging and discharging
Severe gassing:
Charging voltage pushed beyond 2.4 volts a severe discharge take place.
Galvanic batteries
Chemical reaction when electricity is generated when two dissimilar metals are placed in an electrolyte
Primary batteries
Chemical reactions are not reversible; battery can't be recharged
batteries
Convert chemical energy to electrical energy; they also provide starting power for engines and operating electrical accessories whenever engine isn't running
Selecting batteries depend on
Current needs for key off loads, operating electrical accessories, engine type, engine size, climate conditions
Deep cycle- deep discharge
Delivers longer, steady level of power for much longer period of time that SLI batteries, supplies current to constantly powered accessories, supplies power to move inverters
Starting lighting and ignition batteries(SLI)
Designed for short duration deep discharge up to 50 percent discharge during cranking
Dissimilar metals placed in electrolytes form:
Electrodes
Flooded acid batteries
Electrodes are made of thin lead plates submersed in liquid electrolyte.
Type of lead acid batteries:
Flooded cell, deep cycle flooded cell, valve regulating acid battery(VRLA), sealed lead acid battery(SLA)
Batteries connected in series to supply
Higher voltage
Two dissimilar metals
Insulator material separating the metals and electrolyte
Traditional automotive type battery is:
Lead acid battery
Lead acid batteries:
deliver high rates of current with high tolerance, hold charge and longer shelf life when dry, least expensive to manufacture, available in ranges of sizes and capacities
Separator plates
separate positive and negative plates from touching and short circuiting
Electrolytes thicken in cold weather causing:
The battery power to drop
Electrolyte mixture
36 percent sulfuric acid and 64 percent water
Engine resistance increases:
50 % to 250% in the winter
Sulfation happens when:
A battery is in discharge state for too long, continuously undercharged or left discharged
Amount of amperage a battery supplies is:
A function of surface area of the plates
Electrical capacity
Amount of electrical current a lead acid battery can supply
Electrolyte
Any liquid that conducts electrical current
Dry batteries have:
Longer shelf life and lighter to transport
Internal resistance of batteries depends on
Materials used to make plates and chemical composition of electrolytes
Amp Hour
Measure of a batteries capacity
Refractometer:
Measures density and battery electrolyte
Battery state of change
Measuring specific gravity or density of an electrolyte
Batteries connected in parallel supply
More cranking amps
Battery cases are made of
Poly Propylene
Secondary batteries
Rechargeable; based on principles on galvanic reaction; are most practical in automotive applications
Traction batteries:
Rechargeable; used for propulsion in hybrid electric vehicles
Electrolysis
Releases both gases (hydrogen and oxygen)
Squeeze bulb and float type hydrometer measure:
Specific gravity of fluids
Batteries functions
Store energy, act as a shock absorber and operate electric drive traction motors
Battery shelf discharge rate depend on:
Temp and materials used in manufacturing
Batteries are classified by:
Their use, how their made, type of plate materials, chemistry used to provide current.
Separator plates are:
Very thin porus, glass fiber plates allowing electrolyte to diffuse freely throughout cell and prevent plate contact
Material from which electrodes are made and type of electrolyte determine:
Voltage potential of a battery
specific gravity
measure of density