I have an arduino nano and a robot with 2 wheels,I use the l293d driver and I also use "DC Motor in Micro Servo Body" (find it in Google).
My connection is here :
The voltage range for my motors I use (find it in Google as "DC Motor in Micro Servo Body") is 4-6 Volt,current = 650mA , speed = 130 RPM
So, I use a 9 Volt battery for my 2 motors.
My question is if there is any problem for the motors (or arduino).
I hope you help me...