The more energy we store in a battery, the more devastation it could cause when broken or damaged. But how much energy do we store in our 18650s, exactly?… Let's take a 2,750 mAh battery for its face value: 2,750 mAh and 3.7V. 2.75 Ah * 3.7V = 10.175 Wh. 1 Wh is 3600 Joules, so we have 10.175 Wh * 3600 = 36,630 Joules of energy stored in a single battery. Let's take gasoline for a comparison, assuming that we have an "average" gas with 33,400 Wh / gallon energy density, or 120,240,000 J / gal. 36,630/120,240,000 = 0.0003046407186 gal, or 1.15ml of gas. : 18650 cell stores about the same amount of energy as 1.15 ml of gasoline.