The V2 and V2b both use the Mini USB cable, and the V3 uses the Micro USB cable. These are different cables. However, if you're missing your USB cable, we would certainly be happy to get one to you, but these are easily accessible at any store that sells electronics. I will attach a photo that shows the difference between Mini and Micro USB cables.
Also, just as another reference, the Micro USB cable is your typical Samsung phone charger. The Mini USB cable is a regular PS3 controller charger. You can usually find these laying around the house if you've collected any amount of electronic devices over the years.
If you're not sure if you have a V2 or a V2b, please reference the photo below: