I have the Novak HV6.5 in my 3906 flm maxx and it has way better performance then the stock titans. I oonly run nihms 7-cells and the system works great. Very easy to use also and you will get more runtime out of your batteries. I also have a titan powered 3905 and the heavier flm 6.5 hvmaxx outperforms the titans 10 fold.