I have the big OFNA box with the single 12v motor and gell cell.
Yeah it may be a little heavy, but I cant remember the last time I charged it, I bet Ive raced 3 race days with it, 4 weeks total because I skipped a week of racing. Ive even started other peoples trucks on this same charge because their box was dead

Believe it or not, my MRC 959 charges it too