The guys that use lipos a lot - plane guys that fly all the time, say that time spent at full charge is cumulative and its damaging, you don't want to spend anymore time fully charged that you have to.

I used to charge my lipos when I finished running, but now all I do is check voltage and as long as its 3.7 - 3.9v/cell, I leave them be until I get ready to run again - then I charge them fully. If the voltage is lower than I want, I put them on charger and charge them to storage.