Lipos charge using a sequence called CC/CV - constant current/constant voltage. It will charge at CC until it reaches full voltage for the cell count (2S = 8.4v, 4S = 16.8v), then charger switches to charging at CV and the charge current will slowly fall until its zero which is where the charge is finished. This is the special charging that is needed for lipos - CC/CV and is different from charging used for Nxxx, and other types of batt chemistry.

If your lipo is new, it will need a few cycles before it will show you what its really going to be like capacity wise. Keep temps reasonable during these early cycles to get longest life and best performance.