You can do it. A 2s on the BEC lead and a 3s on the non-BEC lead. Just keep in mind that it's out of warranty.
IIRC, Novak themselves did this with their HV Maxx at the World's Fastest RC Car Challenge.
Novak did indeed use 5s with the hvmaxx. I have been running 6s a123 through a novak super duty for a couple of years now. I use a fan but so far so good.
Novak did indeed use 5s with the hvmaxx. I have been running 6s a123 through a novak super duty for a couple of years now. I use a fan but so far so good.