As edlex said, you do not want to regularly let a lithium battery discharge too much too often if you want it to have a long life.
Ni-Cad batteries needed conditioning, but what you did to lengthen their life will shorten it for Lithium.
I charge my battery at 40% whenever possible. If you are going to store your device for any length of time, have more than 40% charge, but not 100%. I cannot remember the exact reason, but it was something about electron mobility.