Hello JT,
I am not sure how fast you can charge, keep monitoring for heat build up within the pack. The only problem with the CG-340 is that its maximum charging rate of 1.5 amps falls in the 0.33C charge range. There are problems with missed terminations when charging at this rate.
You can select a slower rate and time the charge, or use 1.5 amps and make sure you don't miss the timer signal.
Your first charge should be 450 mA for 16 hours to form the pack and bring the cells into balance.
Tom
Tom