I have an iPad 2 that has been great for the 3 months I own it. However, this morning I woke up to a fully drained battery. It had the smart cover on it and it's like there was no sleep mode overnight. Any ideas as to why the battery drained down completely? I believe the iPad had around 88% of battery life last night. So, from 88% to zero overnight with the smart cover closed on it. Thanks for any input.