Do I have to keep the main battery on during the whole flight(from gate to gate)?
If you want your avionics and screens yes. This is what powers them. :)
Hi! Yes, you should,buddy!
Do i have to keep it on in flight
Yeah. Turn your battery and APU on at the start. APU off when engines are on. APU on before engine shutdown. Battery off at destination gate.
Yes. You don’t have to but if you want your screens on then keep it on. This is to never be turned off until final shutdown of the aircraft.
Ok thanks for the help
Answered above :)