Cells And Batteries Flashcards
Two basic types of cells
Primary and secondary
A rechargeable battery is classified as a…..
Secondary cell
What causes the difference between the open circuit terminal voltage of a cell and it’s terminal voltage under load?
A volt drop due to the internal resistance in the cell
What is a battery ?
A number of cells connected in series which are housed in a single case.
The open circuit voltage or emf of a cell is dependant on what?
Materials used for the electrodes and electrolyte
What two basic factors affect the capacity of a cell?
Plate mass and plate area
What are the three main types of lead acid batteries?
Flooded cell
Gelled electrolyte
Absorptive glass mat ( AGM )
What is the positive electrode in a lead acid cell?
Lead dioxide or lead peroxide
What is the negative electrode in a lead acid cell?
Spongy metallic lead.
What is the electrolyte on a lead acid cell?
Sulphuric acid and water
What two materials are used for the plate electrodes in a lead acid cell?
Lead dioxide or lead peroxide
Spongy lead
In a fully charged lead acid cell, the specific gravity of the electrolyte is between….
1.25 and 1.28
The electrolyte used in a lead acid cell is?
Sulphuric acid and water
As the lead acid cell becomes discharged, the gravity specific gravity of the electrolyte……
Decreases
What is the open circuit voltage of a charged lead acid cell?
2.1 V
A lead acid cell should be charged before the terminal voltage reaches….?
1.75V
What happens to the efficiency of a lead acid battery when it is subjected to cold temperatures?
It decreases
State 3 advantages of using a gelled electrolyte instead of lead acid cell.
Lower maintenance
Operational in any position
Corrosion resistant
What are two types of vrla batteries
Gelled electrolyte and AGM
The open circuit voltage of a ni cad cell is 1.2 volts, how many cells would a 12 volt ni-cad battery require?
10 cells
The electrolyte in a ni-cad cell is?
Potassium hydroxide
State four advantages of using a ni-cad battery ?
Higher weight to energy ratio Faster to recharge Long lifecycle Low internal resistance Long shelf life without need for recharge
The electrodes in a ni-cad are made of?
Nickel hydroxide and cadmium hydroxide
