iPad mini 5 battery draining overnight
I have an iPad Mini 5 64gb (16.3.1) purchased new in April 2021, which I keep on a bedstand overnight. Some nights I leave it plugged in to recharge, other nights that's not needed. In all cases, it's left in Airplane mode, Bluetooth is off and cellular is off (no SIM card). Strangely, during the past week on the three nights it hasn't been charging, I've awakened several hours later to find the battery indicator down 20-25%, e.g., 91% --> 69%. OTOH, I haven't seen this happen during the day, even with Airplane mode turned off and wi-fi connected. My bedroom temperature overnight is typically in the low 60's F. Any ideas why this might be happening?