Im not familliar with the battery youre looking at, but I have 2 thoughts. If the discharge cord is the output, and the charge cord is the input (the battery instructions should tell you this) then you will need to use both. You would plug the charge cord into your charger to fill the pack, and the discharge cord to the plane to empty the pack.

If the discharge cord is meant specifically for running the battery through a discharge cycle, then I would say that is simply an option. Running the pack down by using it then charging it back up should be just fine.

In either case, the battery should be ok, and the instructions that come with it will tell you how to hook it up.