Need help choosing a battery for powering stepper motors

[razvi9]

The current configuration I have is:

• a quadstepper controller: robotshop.com/en/quadstepper-4-stepper-motor-driver-board.html
• 3 x stepper motors of this type: robotshop.com/en/bipolar-stepper-motor-2-7v-1a.html
• I am controlling it with an arduino pro mini but that has it’s own 9V battery

I’m not really sure what battery to buy for this configuration (i.e. what voltage and amperage?).
Could you please give me some advice on how to choose a battery for my configuration?

[cbenson]

Since you have three ~1A motors, your power supply should be at least 4A. You can power it at anywhere from 2.7V to 12V+, the choice is really yours. If you opt for 12V, you would only need one power supply.