Yup, you can. If you wire then red to red, black to black, you will keep adding to the mah of the pack. This is known as wiring in parallel. If you wire then up red to black, red to black, leaving one red and one black on teh ends, the mah will stay the same, but your voltage will go up. Just make sure what you are using can handle a 6s pack, or 22.2 volts because that is what you will be pushing if you wire 3 2s packs in series.