Z-LCD automatically shuts off its display below 50ºC - when your extruder heats up above 50º the display will come on. There is a capacitor at the input which holds charge, so during shipping the display may be on (until the next PCB revision when I will add a resistor to discharge the capacitor
). The difference in battery drain with the display on vs off is miniscule, so don't worry that your battery has been depleted.
