battery

I have recently puchased an ipad 4 and I have noticed the battery level appears to drain rapidly whilst not in use.

As an example, in less than 24hrs. Half of the battery life has depleted.

Updated to 6.1 in the hope that the issue would be resolved, even fully discharged battery in the hope of recalibrating it.

Unsure how to proceed? Is it a faulty battery.

A friend has an identical model. In three hours, I had lost 15% vs his 0%.

Any suggestions would be welcome