Maybe I should have described this better than I did the first time.
Our trailer is parked on our driveway that is about 10 feet lower than the house, and it is more than 100 feet from the trailer to the house (toilet). This is too much of height difference and too much distance to dump directly from trailer tank to toilet even with macerator pump (and sewage clean-out is even farther away).
So I use two step process:
First I empty the trailer tanks to a portable waste water tank (
Thetford SmartTote)
Second I bring the tank closer to the house.
This is where I use the macerator pump from the portable tank to toilet (I needed a unique adapter, but that's another story).
So where macerator pump operates is far away from where trailer is, and that's why I can't use the trailer batteries.
I could bring my tow vehicle to the pump, and I have done that a few times. But it's just a pain in a neck to do so because I have to move my outdoor furniture, etc. (sorry if I sound lazy).
That's why I was hoping to find a generator (I wanted to buy a generator anyway) that has
12V + 20 amp output. But I don't think there is such generator (not at least among the inverter generator).
But I guess I could just buy a cheap battery to operate the pump.
Then come to think of it, I have an AGM battery that is rated 3 Amp Hour that I had bought for a totally different reason. All I need is to run the pump for 3 minutes (1/20 hour). So 20 Amp x 1/20 Hour = 1 Amp Hour is all I need, right?
But such small battery may not be able to discharge 20 amp?