When you set up lipo on the Ice in lipo mode you set the voltage (number of cells) and then lipo capacity (mah). Use 1600 since you can't select 1650mah. The charge rate can be set up to a 1C maixmium (1C = 1650/1000 = 1.65amps) which is based on what you input for capacity. Since you input 1600 as the closest to your lipo capacity, your max charge rate will be 1.6amps.

The autobalance built into the lipo will keep cells balanced.

BTW, if its 11.1v, its a 3S not a 2S, 2S is 7.4v.