If you touch only a positive side of a battery you will NOT get a shock! You would have to touch both positive and negative to get a shock or touch the positive side only and ground yourself to whatever ground the battery has. You would need an inverter to go from 12 volt DC to 120 volt AC. An inverter is a device that changes a 12 volt DC car battery into 120 volts AC, and that can be used to run normal household electricity for a short period. You can run your lights, TV set, refrigerator, VCR player, DVD player, computers or power tools. You wouldn’t be able to run all of the above at the same time because the battery would drain too quickly.

Assuming you really want to know about 12 volt DC batteries like are common in cars, (not 120 Volt DC batteries that are extremely uncommon), the answer is no. Generally DC voltages below 50 volts are not considered dangerous, and those above are potentially dangerous. There is no shock hazard from the battery in a car, but it can still be dangerous if it is banged around, connected to something that can not handle its power, or shorted out. The battery contains acid and if it is banged around the acid can leak out and hurt you, you clothes and the paint on your car. If there is a short in the wires connected to the battery they can get very hot and burn into and through other things, or start a fire. If the terminals are shorted against a large conductor, like a mechanics wrench, the current in the battery may cause a lot of sparking, hurt the battery, and even cause it to explode. People who report being shocked while touching things inside cars engine compartments are not lying; they just don’t know what shocked them. All cars gasoline engines have ignition coils, distributors and spark plugs, to ignite the air fuel mixture inside their engine cylinders. The coil amplifies 12 volts from the battery to about 40,000 volts, (at a very low amperage), so that it can create a spark across the tip of the spark plug. Anyone unfortunate enough to get shocked by the ignition system will receive a very strong and unpleasant, but not dangerous shock. High voltage shocks are only dangerous if they also contain enough amperage to be dangerous, and the ignition sources in cars do not.

you can get shocked from BOTH sides...depending on how you are grounded be careful