go here to read about installing the sani-con... This may not be your exact sani-con model but the install information will be the same... I was going to download your exact sani-con but my computer alarmed saying it might contain a virus so I didnt download it.
RV SANI-CON InstallConnecting directly to the battery terminals is fine but you must use a inline 20AMP fuse at the battery that looks similar to this. This fuse is to protect the wires when shorted out from getting smoking hot and not burn your trailer down... AS the manual states be sure your connect the correct polarity. Otherwise your sani-con pump will run backwards...

Roy Ken