how many charge cycles does the ipad battery have?

There is no set amount of charge cycles. Apple's claim is that the battery should retain 80% of it's original capacity after 1000 charge cycles.

Charge Cycles³

A properly maintained iPad battery is designed to retain up to 80% of its original capacity at 1000 full charge and discharge cycles. You may choose to replace your battery when it no longer holds sufficient charge to meet your needs.

http://www.apple.com/batteries/ipad.html