Portable Power Inverters - 12 Volt Power inverters are designed to turn 12 volt DC into 220 volt AC current. These are the most common power inverters and are used in most cars, Trekking, expedition and other needed aria where electricity is not aviable. Most 12 volt power inverters under 1000 watts have two connection methods available. Plug type power inverters which plug into the cigarette lighter socket usually are rated up to 500 watts. Power inverters rated over 150 - 1000 watts are generally hard wired direct battery connection types.