Plug in America's website says that frequent fast DC charging can be bad for a battery. Is this true for supercharging Tesla's batteries? This is what they say: DC Quick Charger An offboard charger that connects directly to a vehicle's high-voltage battery bus. Allows for high power transfer and can charge a battery to 80% or so in minutes instead of hours. Quick charging should be done according to vehicle manufacturers specifications, as this charge method can be damaging to the battery if done too often.