A cordless shop vacuum can be used for wet vacuuming tasks as well as dry. There are a number of cordless wet vacuum models on the market today that are relatively powerful. Do your research before you purchase the first cordless shop vacuum you see. The updated cordless wet dry shop vacuums are portable, lightweight, compact, and powerful. Because of the size of the motor that power these battery-powered shop vacuums, the noise level is somewhat lower than the conventional wet dry vacuums. Keep in mind that because of their smaller size, the volume of liquids these cordless vacuums can hold is on average about 2 gallons.
For more info, see A Car Vacuum Buying Guide