I use an inexpensive 12 volt submersible bilge pump that fits into the opening of a 7 gallon Aquatainer. Ten feet of clear hose on the discharge and alligator clips on the wires completes the setup. It takes a few minutes to transfer the water, but I'm on vacation and not in a hurry.
Geoff & Jill
& Sierra, the little white monster
2013 Ford F-150 XTR SC Ecoboost
2015 Jayco Jay Flight 24FBS