A 12-volt electrical system operates on 12-volt current rather than the more typical 120-125 volts located in most homes and businesses. A 12-volt electrical system is common in recreational vehicles, camping trailers, cars and trucks. Those with solar power systems often use 12-volt systems.
Any device that plugs into a vehicle's cigarette lighter or power outlet is running on a 12-volt current. This lower voltage is safer to use than 120-125 volt power due to the lower risk of electrical shock. It is possible to use smaller wires for 12-volt power as well. Twelve-volt systems have received a lot of attention due to the increased use of solar panels by many homes and businesses.
Sometimes it is possible to convert 12-volt power to 120-125 volt current with the use of an inverter. Many on-the-road truck drivers use 12-volt power for devices in the cab of the truck or sleeper. Boats are another common place to find 12-volt systems.
A lower voltage current can be useful in applications such as starters because it makes for a quicker starting engine. Twelve-volt systems are easier to work on than 120-125 volt systems because of the smaller gauges of wire used and their overall lack of complexity.