I have a portable Sanicon macerator, i.e. the
"TankBuddy", that I carry "just in case". It comes packaged in a tool box and works fine.
Since I don't use mine regularly, I did not bother to rig a permanent 12v line to the utility bay. Instead, I run an extension cord with large alligator clips to the battery bank (opposite side of coach) when needed.
Rather than carry a heavy duty 12v cord just for the purpose, I built a pair of adapters that allow me to use a heavy duty (10 gauge) 120v extension cord for most of the distance. A 10 gauge cord will carry 30A, which is a little above the max draw of the macerator pump. The 12v leads are wired to standard 120v plug using the ground and neutral leads to carry the current. That way, if somebody mistakenly plugs the other end into a wall socket instead of the battery clip lead adapter, nobody gets electrocuted!