Hi
The electrical system in FS9 is real buggy
If you have saved a senerio with an aircraft that has normal electical power then switch to an aircraft that has electric_always_available 9 out of 10 times fs9 ingnors it.
Ive notced that when a battery go's flat it only drops to 16.9 volts so opening the aircrafts.cfg and looking for the electrical section you can drop the required voltage to a lower level here is an example that will do the same thing as electric_always_available and works 90% of the time
[electrical]
gear_motor = 4, 1 , 1
light_wing = 0, 1 , 1
light_logo = 0, 1 , 1
autopilot = 0, 5 , 1
avionics_bus = 4, 5, 1
avionics = 1, 5 , 1
additional_system = 2, 1, 1
marker_beacon = 1, 1 , 1
gear_warning = 0, 1 , 1
fuel_pump = 0, 1 , 1
starter1 = 0, 1, 1
light_nav = 0, 1 , 1
light_beacon = 0, 1 , 1
light_landing = 0, 1 , 1
light_taxi = 0, 1 , 1
light_strobe = 0, 1 , 1
light_panel = 0, 1 , 1
also droping the ampage for which each entry uses will extened the life of the batt
1st # is the bus
2nd # volts
3rd# is amps
hope this helps
Wozza