How do I power multiple 3.0 kg-cm 4 Wire NEMA 17 Stepper Motors?

I'm currently doing a school project in which I am motorizing a tripod. I'm trying to use two stepper motors on one Adafruit motor shield and another stepper on another motor shield on top of that. How can I power this without draining the battery quickly. I'm hoping to be able to use re-chargeable batteries.

The specifications for the motor are:

Step Angle: 1.8o +/- 5% Voltage: 9.0V Current/Phase: 0.4A Inductance/Phase: 20mH Resistance/Phase: 22 Ohm Max Static Torque: No of Phase: 2 Holding Torque: .2 Insulation Glass: B Insulation Restiance: 100Mohm(500V DC) Compatible with these Controllers: XCW220

With stepper motors you are draining the battery quickly, pretty much guaranteed, since they take lots of power when not even moving.

Use of worm gears can mean no back-driving is possible, allowing powering down of your motors when not in use, and using DC motors with encoders would be less power hungry than a stepper anyway (but more complex to drive).