12 volt socket 120 watt limit

You could cut the plug off the compressor and attach a couple of alligator clips. It could then be connected to the under hood jumper connection or directly to the battery.

I managed to find one at Wal-Mart a few years back for about $20 that draws less than 10 Amps. Of course when you get a cheap one like that they are only good for a few tire inflations then they usually break.

 

A better solution is to make a "pigtail" that you permanently connect to the boost terminal and ground with a connector on the other end. Put a 20-30Amp fuse in it and the socket type connector on it! Put the mating connector on the pump cable. Pearl has one for battery maintaining while sleeping over the winter. The connector used doesn't have to be waterproof as long as the sockets in it are fairly widely spaced. I use a Molex nylon type, as they cost less than $1 and are readily available.

Just take care to remember you mustn't exceed 150A draw from the boost terminal (something you probably couldn't do anyway due to the wire resistance).

 

I have one of those portable compressors that plugs into the 12 volt socket.
However, one of the first things I purchased after buying my Prius was one of those "portable" all purpose Jump Start, Compressor/Emergency light/Power systems.

The advantage/disadvantage is that it recharges on home plug in electricity then can be used stand alone, I don't have to worry about plugging it into The Prius.

The disadvantage is that since it's basically a sealed battery and a compressor, it's pretty heavy and I store it at home indoors.

But as far as a compressor that I can use in the driveway to check and maintain tire air pressure, that is what I plan on using from here on out.

 

The Gen 3 can handle more than 700W?

Reads like above and in this link:
how big 12v power inverter can i run off my Prius for generating power? | PriusChat

I recall the Gen 2 limit 700W if I'm remembering correctly for doing similar with an inverter for an AC outlet.

Nice to know can tap 100A for a 1200W inverter directly... granted I last left off considering a soft or hard start capacitor installed on the device input or inverter output.

 

1kW has been sort of the magic number for every generation of Prius I've been around. The car's DC/DC converter tends to be good for 100-ish amps, but some of those have to be for the car. The fusing at the two ends of the cable between it and the battery has varied in the neighborhood of 100, 120, 125, 140 amp depending on generation and which end of the cable. Output from the converter will begin to droop, as Bob Wilson found, as you get up toward that maximum (also depending on what loads built into the car are also in use).

It's possible to attach a bigger-than-1kW inverter, just not likely to get much more than 1kW out of it, at least for very long.

 

I dedicated a deep cycle battery for the 120VAC via the 1200W inverter use and a charger that I'd use at 3A charging with a 175W inverter from the 12V outlet to charge the deep cycle. Now days I'm wondering about the Artek power bank or bank of those to use since easier to fit and integrate for larger power demands. Different lifestyle now not on the road doing advocacy.

Haven't read about Bob Wilson before. Searched and found this link:
Prius - UPS Project

While at it, I recalled the Woody Wagon and search for the 700W reference that was coming to mind, found to be 800W now reading:
FD Prius Power