Youcan get UP TO 3 hours out of the 600 mah pack with 200 ma current drain. You should be recharging at close to 1.5 to 2 hours if you want to be safe.

It is always better to recharge early than to find out you have no power left in the TX or RX with the airplane in the air. The last model I saw that crashed from dead battery had no salvageable piece larger than a clevice.