Older speed controls may be able to handle the voltage of a lipo, but the amps might not be supported. Better to get a lipo specific setup, something with the auto cutoff built in to protect your lipo batteries. Check out
www.castlecreations.com, they make good stuff a reasonable price. Do your home on lipo's and balancing and what not. I balance mine only when they need it, meaning a cell is off by .1 or more.