Rick:
For long life of nimhs I charge mostly at 1c or in your case 300ma. If Im like you and need a pack charged at the field I do fudge a little and charge at 2c or around 600 ma in your case. If yours is a new battery it will take 3-5 charge- discharge cycles to "come in" to full capacity. Some larger new batteries also need a "forming" charge at c/10 for around 12 to 16 hours at say 50ma from a TX type wall charger. If you are going to charge at over 1c keep a eye on them so they dont overheat them . Warm to the touch is OK but hot to the touch will kill thier lifespan.
Good Luck
Bob

PS--The dusk-stick is a sweet flyer. Never had one but have seen them fly, Kind of slow and graceful like a slow stick but not as ugly.