I’m new to having a glass panel and know precious little about avionics and electrical systems, so this may be an obvious question, but how do you supply power to a glass panel (so that you can install database updates, configure screens, etc.) with the engine off? Can you just put a trickle charger on the battery and then turn on the battery half of the master rocker switch? If this has been asked and answered, can someone direct me to the link? I couldn’t find it via a search. Thanks in advance.