Apple messed up one thing about the iPad, which made me never use mine and eventually give it away. Basically, my iPad would die in a couple days if left unplugged. Because I only want to use it about once a week, that means I have to leave it plugged in all the time. Of course I or someone else inevitably wants to plug something else into that charger, so the iPad gets unplugged and forgotten about. Then, in a week…
Something wrong with your iPad then. All three of mine would easily hold a charge for more than 2 days even when turned on but unused (so asleep).