You shouldnt be worrying about the mAh as much as the amps in a battery if your planning on getting the nemsis. If your going to sub ohm which im assuming you are you need to get at least a 20-22 amp battery, preferably a 30 amp just to be safe. The mAh just determines the battery life, but that wouldnt matter if you sub ohm with a 10 amp battery exploding in your face. Good luck and hope this helped!