Which lipos for 9xl & 9920? Please help. 10c?15c?20c?

Originally Posted by 4u2nv

Would these batteries be ok?

http://cgi.ebay.com/11-1V-4000Lithiu...QQcmdZViewItem

OK, I'm going to clear up my question. I'm asking if I can use the batteries above with a 9920 esc and a 9xl motor. I will be using 2 - 11.1v 3s packs which should make 1 - 6s pack if I'm correct. So It should make a 11.1v 6s 4000mah 15c. Will this be good? What can I expect for speeds?