Yeah, no problem (assuming we`re not talking a 30 ft. motorhome). If you run it flat out on the trigger (765 CFM), it`s only about 20 minutes but the handle has a dial on it that I believe limits it to 580 CFM and though I`ve never timed how long it will run, I have a ton of concrete in my yard, probably 20 minutes clean up lawn clippings. I can probably handle the entire yard 2 - 3 times before I just instinctively throw the battery on the charger.
I`ve never run it all the way down and drying a car takes perhaps 20 minutes tops. It`ll do that with ease. The trigger is variable speed so as long as you aren`t squeezing it for everything it`s got I can`t imagine you`ll have issues drying a car. It has a light (gas gauge so to speak, round with 5 sections) on the back of it. You can monitor how low the charge is getting.