You say this is an 8.4 volt 1300 mah pack so I assume it is 7 NMH cells of 2/3 A size weighing about 21 grams per cell. If this is so, 3/4 to 1.5 amps ought to be about right. It should take between 30 minutes and 1 hour to charge an empty pack, the potential across the pack should not exceed 1.65 volts per cell (11.55 volt for the pack), and the pack should not be hot when charging. At the end of the charge it should be pleasantly warm. Cycling occasionally helps but is not neccessary every flight — just top it off to peak. A slow C/10 charge is advisable the first time you charge to prevent overheating the weakest cell. I wouldn’t completely empty the pack either — take it down to 7 volts (1 volt per cell). When you cycle it, about 3 amps is good — I use two 1156 auto bulbs. If your pack is lithium, disregard this.