I am buying a HUD Head Up Display. It goes in Sleep Mode when ignition is off (screen turns off). I asked the manufacturer, they said it uses 0.3mAh when in Sleep Mode (400mA while in use).
Is this enough to drain the battery? I know 0.3 is probably not a lot, but who knows. Manufacturer also suggested me to unplug it if I don't use the vehicle for a week+.