DeWalt DCV581H vs DC500
The DCV581H wet dry vacuum is designed to operate on a DEWALT 18V NiCd/NiHiD/Li-Ion battery pack, 20V Max Li-Ion battery pack, or a 120V AC input.
Whereas the DC500 is designed to run off of a 12.0, 14.4, or 18V DEWALT battery pack, or 120V AC input.
The DC500 has a drain port on the tank for quick, spill-free disposal of liquids.
It seems that the DCV581H does not have the drain port.
If you know other difference between DCV581H and DC500, please share below.
Pages to download manuals to learn more.
DC500 Manual – http://servicenet.dewalt.com/Products/Detail?productNumber=DC500
DCV581H Manual – http://servicenet.dewalt.com/Products/Detail?productNumber=DCV581H