I wouldn't suggest trying to take energy from a spirit, as it could potentially open you up to a number of nasty things if you were not properly grounded. Also, depending on the spirit, it could anger them.
If you are considering this, I would try and ask the spirit if it is ok for you to use some of it's energy. Even if it says yes, be sure that you are properly grounded and protected before you even try.
Again, I wouldnt suggest this as there are also many easier ways to receive energy than from a spirit and this method is probably not the safest.