I have a JR 7202 heli version, and a JR Sport s400. I do not have a battery for the s400. Do I need one. I was told I can buy a cord from radio shack to connect the two. It looks to be a standard double male adio cord. Is it a mono or sterio connector. How do I set the two up once I have the proper stuff. I don't even know who holds what and how.