battery help

[jlustig83]

I have a 3906 emaxx with a mamba max esc and a fiago 8xl motor . The question i have is why are my batteries getting so hot when i only have the truck geared to go 30mph with 18 tooth pinion and stock spur 32 pitch. Im running 12 cells 3500 tenergys nimhs. the esc and motor stay under 150 degrees but the batterys hit 200 plus the other day after the 5 volt cut off . I would really appretiate any suggestions. thank you.