As Sea Angel we have a small 12 volt 1 gallon wet/dry van. It also does most of the inflation of the dinghy, so dual purpose there. You can suck the last of the water out of sumps etc with this also. Stanley makes one. Ours is a cheap Chinese version I got at wet marine on sale a couple of years ago, but it is surviving.
We have been impressed with the Ryobi one plus Lithium ion battery, and are carrying the (2 million cp) spotlight, a 18 volt fan and would consider the Ryobi hand vacuum, to all use the same battery, and there is a 12 volt charger.