Need some lipo size help here

I suppose things have changed in past couple of years, I used to have a RC18 that I had a Mamba 25 esc with a 1800 3 cell and mamba 6800 motor, I did run it with larger wheels 1/10 scale sedan foams and when I would get done with a run I could start a forest fire...., I eventually fried the esc I now have the truck in my garage gathering dust