[RC-Monster Mike]

To run 40 volts or more, you would need a very slow turning motor(around 800 rpms/volt). The 18 cell controllers (actually, they are approved for 20 cells) are good for 100,000 rpms with 2 pole motors. The 30 cell controllers (approved for 36 cells) are good for up to 42000 rpms, so they require slow turning motors. I don't have any motors in stock that would work with 40 or more volts. I could get something like this, but I don't stock it. I was suggesting wiring the two packs in parallel (so, 22.2 volts and 6400 mah) using the 18120 controller. So two 6s LiPo packs, but acting as one larger pack.