Hi I am trying to drive two 5v DC stepper motors the problem I am is that when I am connecting my arduino uno to a 9 volt battery the stepper motors don't want to rotate, but when it's connected to my laptop they do work, it's only when I try and using the 9 volt battery as my power supply when I see that the stepper motors don't work. I think I need a a higher voltage power supply and current, but the question is how much voltage and current.
As You don't attach a wiring diagram, no specification for the battory, I have to guess.
The battory is of the size of a matchbox and is way to poor. If You power the Uno first it will start but when You connect the servos the UNO will staevae, not having enough current.
Give us more info and facts and You will get better answers.
The PP3 style 9v smoke alarm batteries are totally unsuitable. They cannot provide enough current.
From your description I suspect you are powering the motors from the Arduino 5v pin. That is not a good idea. The Arduino 5v pin is not designed to provide enough current for motors.
One option would be to power the motors from a pack of 3 x AA alkaline cells (4.5v) or a pack of 4 x AA NiMh rechargeable cells (4.8v) and then you could also power the Arduino from the battery pack by connecting it to the 5v pin (and GND).
Even if you are not powering the Arduino from the motor batteries make sure to connect the battery GND to the Arduino GND.
...R