Like with everything- each design has its specific advantages and disadvantages. The advantages of the corded design are that it will never run out of steam. If you really want to take your time to ensure that you get to every time nook and cranny- there is no ticking clock of a corded design. Of course, with cords also comes with the risk that it may be too short and won’t reach the back of your SUV. The cordless features allow you to reach every part of your car, but they typically run time on these designs is about 30 minutes, even with the utilization of lithium batteries.
Once the battery is dead, it typically takes about 5 hours before it will be fully charged and ready to work again. When selecting which type is right for you- think about what is more important. If you are historically bad at remembering to charge things when you are done using the- then cordless will probably not be that much of a help to you if it is constantly dead. However, if you want something that you can use in places other than automobiles- the cordless version might be perfect for your needs.