Batteries Flashcards
What two things do batteries do?
Start power to engine or APU and power if other sources fail.
What does a primary cell mean?
One usage.
What are the three batteries used on an aircraft?
Lead / nickel-cadium / lithium
Battery discharge is considered to be an x condition.
ON LOAD
To recharge a battery, the applied voltage must be blank% blanker than the OFF - LOAD normal voltage.
15 % higher.
Under normal circumstances it should take around x minutes to fully charge a battery following an engine start.
20.
What is the units for battery capacity?
Amp hours.
How to contain battery thermal runaway?
Vented metal box that completely covers the battery.
What is the worst case scenario if thermal runaway occurs?
Fire.
The flight crew has to be notified if a large amount of lithium batteries are being carried in the hold as…
They are prone to blank if overheated.
Thermal runaway.
Most aircraft batteries used during flight employ a Constant Voltage Charging system to sustain them in a fully charged state. This system ensures that the generator’s output voltage remains steady at x volts for a 12-volt battery and x volts for a 24-volt battery.
14 28
The voltage of a fully charged lead-acid battery cell under no electrical load is… x volts.
2.2volts
An advantage of nickel-cadmium compared with lead-acid batteries is that they…maintain a constant output voltage during x.
Discharge
In a multi-cell lithium battery, one cell sets on fire. The fire will/wont spread to other cells.
Will
Batteries connected in series increase voltage/current/resistance
Voltage
Batteries connected in parallel increase voltage/current/resistance
Current.
The test to assess the state of charge of a lead-acid battery is to…compare the x and x battery voltages
Onload / offload
True or false : The total battery capacity is dependent on the voltage rating of its battery cells
False
If one of the 12 cells of a Lead-acid battery has a broken connection rendering it inoperable, the battery…
Cannot be used.
A lithium polymer battery is most likely to be a hazard to the aircraft when the battery has an extreme blank blank
Internal pressure
What is a major risk to a battery in case of damage or abuse? Bank current and thermal runaway.
High
When the battery ammeter shows “+24” the battery… is being charged/discharged with 24 A/V
Charged / A
A Lithium Ion battery can be considered most unsafe… when the battery has an internal blank
Internal short circuit.
The electrolyte in a Nickel Cadmium battery is… blank hydroxide.
Potassium
A significant increase in battery temperature during charge is an indication of…
Thermal runaway
When a battery is almost fully discharged there is a tendency for the: blank to decrease even under light loads.
Voltage.
An advantage of nickel-cadmium compared with lead-acid batteries is that they… provide a constant output blank during discharge.
Voltage,
.
