The current sense output isn't much use unless you connect the L297.
When using "full steps", both motor coils are activated at the same time, which means that each motor will draw 2 amps total. In theory a single 2200 mAh (2.2 Ah) battery will provide 2.2 amps for one hour but in practice, less than that. With two motors the situation is quite a bit worse (I would guess perhaps 10-15 minutes).