I have a Black & Decker Flex that runs off a cigarette adapter. I won't say it's good, because it's not. But technically it gets the job done. It just takes multiple passes to pick mostly everything, but it's better than nothing. With that said I'd imagine the DeWalt would be better, but I have nothing to base that on other than DeWalt makes good tools lol. It's also a ton more expensive. B&D makes a battery version of the Flex, but the specs are something like 8 minutes of battery power.
For what it's worth it will vacuum up quarters so it has some level of suction.