although you charge lipos at 1c MAX, it will generally take longer to charge then 1 hour on most chargers. lipos charge in two phases, first is constant current, at which point your 1c current setting is taking place. as the voltage approachs the target voltage (8.4 for a 2 cell pack), the charger slowly backs off the current and maintains the voltage. although it depends on the charger, a fully discharged pack will take 75 to 90 minutes to charge (or sometimes longer even)