M3.5 Flashcards
What is internal resistance?
The resistance present inside a battery connect to a load
What does internal resistance do?
Restricts the movement of current inside any battery
What happens to the internal resistance when the battery discharges?
It rises
At what percentage will the internal resistance affect the electrical systems?
Over 75% discharged
What happens if the terminal isn’t cleaned properly?
It offers additional resistance to current and voltage
What is the difference between primary and secondary cells?
You cant recharge primary but can recharge secondary
What is an example of a primary cell?
Zinc-carbon battery
What are the two types of secondary cells on an aircraft?
Lead acid or nickel cadmium (connected in series)
Lead acid cells consist of what percentage split of sulphuric acid and water?
30% of sulphuric acid and 70% water
If a lead acid cell has a voltage of 2V when fully charged, what is its final discharge voltage?
1.83V
If a nickel cadmium cell has a voltage of 1.2V when fully charged, what is its final discharge voltage?
1V
When is the electrolyte level in a nickel cadmium battery at its lowest?
After discharge
When must the electrolyte be refilled in a nickel cadmium battery?
When its fully charged
What are the advantages of nickel cadmium to lead acid?
-better power to weight ratio
-closed circuit voltage
-larger capacity
(However more costly and larger
When batteries are added into a circuit what must be remembered?
They must be the same
