RE: cox electric cl
If that's the small electric I had sometime in the early 70s, I wasn't impressed by mine. Even on the short lines, I still had to whip to get a half-way decent flight. Sorry I can't remember how to charge it. If it is that old, the battery may be gone.
Of course, I have also done a lot of swearing at some engines other people swear by.
Wish I could be of more help.