If you have a 5 cell hump pack. Thats 1.2 per cell nominal voltage. So 1.2 X 5 = 6. When charging your charger will peak out somewhere about 7.5-9 volts. You can safely fast charge the cells at C/1 which in your case would be 1.1A charge current. But the first 3 charges which you should do before putting them into service should be gentle. Somewhere like 200ma charge and discharge at 500ma to 750ma. Give them a bit of rest between cycles.