Need a battery for your Arduino that is high enough to regulate the voltage to down to a solid 5V? Well here comes the 9V Snap to 2.1mm Barrel Plug Cable to your rescue! It allows you to plug in 9V and 7.2V rechargeable batteries to anything with a 2.1mm Barrel jack on it.
These dual VNH3SP30 motor driver carriers are perfect for driving two high-power motors through one compact unit. With these boards, it's easy to get a medium-sized, differential drive robot running in no time. The VNH3 version is a lower-cost option than its VNH2 counterpart.