Batterys Flashcards
EASA C25 Standards for battery’s
Main battery must last 30 minutes after electrical gen failure
Emergency lightening must last for at least 10 mins
Types of battery’s in AC
Lead Acid 2.2v
Nickel Cadmium 1.2v
Lithium Ion 3.6v
Lithium Polymer
Magnetic circuit breaker
Two strips of metal bonded. Current flowing heats them and makes them expand and bend. Not usually used on circuits which need quick response to overcurrent
Not time responsive (need time to heat up)
Nickel Cadmium
Voltage on load 1.2
Alkaline battery
Prone to thermal runaway
Contained in steel box/vented
+ produce large current for start/lighter/stronger/long life/expensive
Lead Acid
Voltage on load 2.0
Voltage off load 2.2
Lead peroxide battery
Voltage decreases with state of charge
Old/heavy
Lithium Ion
Voltage on load 3.6
Used on newer ac/lighter
Thermal runaway
What battery’s are prone to thermal runaway
Nickel cadmium and lithium ion
Negative temperature coefficient
More current = more heat = less resistance = more current
Fire
Battery Capacity in series
Increase voltage but capacity stays the same
10v 5AMH + 10V 5AMH + 10V 5AMH
30v 5AMH
Battery capacity in parallel
Voltage stays the same/capacity increases
10v 5AMH + 10v 5AMH
10v 10AMH
Cold temperature has what impact on battery
Reduces capacity
Increases charging time
EASA CS25 Battery Regulations
Main battery’s should last 30 minutes after failure of generator
Emergency lightning must last for at least 10 minutes
Four Types of battery’s on AC
Lead Acid
Nickel Cadmium
Lithium Ion
Lithium polymer
The electrolyte in nickel cadmium battery is
Potassium hydroxide
Battery condition check
Comparing on load and off load battery voltages via the voltmeter
