It is said that with dry hands, you can touch the poles of a car battery and it will not shock you. I understand this is because dry hands have a very high resistance. Now if you have wet hands, or even worse if you have needles stuck into your skin that are attached to the battery posts, this should reduce the resistance and could shock you. Someone told me that the second scenario (wet hands, or needles in fingers) would not be dangerous. They cited the example of putting a small 9V on your tongue. In this case you only feel a slightly uncomfortable buzz on your tongue. Therefore, because a car battery has only slightly higher voltage, it would be only a slightly worse than this and not deadly. Does the fact that the car battery has so much more capacity than the small 9V not affect this situation? If you connected an automotive battery across your tongue the same way as the small 9V, would it be only slightly worse of a shock? If this is true, then I can see how the important factor is just voltage and not the amount of energy available.