I am using 3.7 V 2000mah battery.
I am stepping it up to power an arduino board via an NCP1402. It has a continuous output current of 200mA.
I am trying to run two Micro Metal Gear motors with stall current 700mA. This setup works fine.

However when I try to use 2 AAA batteries and power it up, it does not seem to run the motors.
Any idea why? Any ideas as to how to overcome this issue?
Thanks!

 

What type of AAA's are you using? NiMH are only 1.2v

 

And look up the current rating of AAA batteries. Even if you can start the motor(s), AAAs could only run the Arduino board (without motors) for ~30min.