Thanks for the info. So it looks like you turn everything on before you hit the start button? I think it's
not obvious when the battery backup kicks in to keep your avionics alive during start. You could verify
by disabling the battery backup and measuring the voltage at the avionics power terminal during
start to see what it does and then turn the backup battery on and see if it's different. Not sure that will
work though since there are 2 power inputs to each avionics device.
One important difference between the 912is you have and the 914 I am planning to use is that the 912is has
2 internal alternators. One is 16 amps and the other is 30 amps. The 914 only has a single 18 amp alternator
which is pretty wimpy considering the engine needs 8 amps to run and the radio can use up to 7.5 amps
during transmit.
Victor