Well, I got creative , bought a Shurflo evolution pump (same as whats in the trailer) and made my own fresh water fill "kit". Used a small Rubbermaid "Roughneck" tote, mounted the pump to a hard black plastic plate (maybe use a piece of old truck mudflap?) and set the plate down into the bottom of tote. I cut the plate so that its a snug fit in the bottom so the pump doesnt move around. I installed a shurflo in-line screen filter. I had an extra 12 foot fresh water hose as a doner hose, cut one 8 foot length off it and added a garden hose repair kit (brass) to the other end. This is my outlet hose to the trailer fill, so I used the remaining hose for my inlet hose. Had to heat the small white pieces of hose (inside the kit) with a heat gun before installing and clamping on the inlet and outlet sides of the pump (no leaks). I have since added quick connects on the brass inlet and outlets so its a really fast set up. To power it, I used 2 sets of 2 pin "battery tender" plugs, with an in line fuse and 12 feet of lamp cord, attached it directly to the battery terminals of the trailer battery. This way, you can leave the one side permanently attached to the battery, just hangs out of the battery box.You can buy these at motorcycle shops for around $5.00 each and you will need 2 of them, (typically used to connect to a bike battery, then plug in for heated jackets, charging etc).
Used a small black plastic "hobby box" (about $4.00), with a 12 volt toggle switch and a screw on waterproof "condom" on the switch. Sealed the hobby box with silicone, so its waterproof. The notch out of the blue bin lip is to allow the 12 foot wiring harness to be put back into the bin for storage with the lid on.
I wanted to post some pics but they are too big so I am sharing a link on drop box.
Click on this link, then will take a few seconds to load. There are 9 pics...
**Might have to try to click on the link a couple of times to get pics to load... I just tried and the pics didnt come up till the 4th time I tried.**
I get enough pressure out of this, that I could screw on a garden nozzle, flip the switch and wash the trailer or my truck with it! The evolution pump will cycle on and off with the nozzle trigger. I leave the one end attached to the trailer while on the site, then just click on the inlet hose when I need to fill the tank.
Will pump a 6 gallon jug in about 2-3 minutes ( would be faster but due to the size of the freshwater inlet fill, it limits the pump).
Really happy with the results!!