Anyone else think a big inverter ruins a portable build?

I went small on my own rolling box and I've never once wished I'd gone bigger. Mine runs a 1000w pure sine unit off a pair of 100ah batteries, and it handles the kettle, a sawzall for quick cuts, phone chargers, and a box fan overnight. The stuff that actually matters during an outage is almost always low draw anyway. The one time I needed more was running a neighbor's well pump, and honestly no inverter I'd want to carry would have liked that surge much. The hidden cost of going big isn't just weight, it's idle draw. A big unit sipping an amp or more around the clock will eat your bank overnight while doing nothing. With 200ah at 24v you've got real capacity, but a 3000w unit idling all weekend is a chunk of it gone before you plug in a single thing.

The other thing nobody tells you is that a huge inverter on a portable rig pushes you toward bigger loads, then your runtime falls off a cliff and suddenly the box isn't grab and go anymore, it's a semi permanent install that happens to have wheels. If I were you I'd list the actual AC stuff you'd run at a campsite, size for that plus maybe twenty percent, and stop there. Mine has been plenty for three years of camping trips and two outages.

I land somewhere in the middle, and my reasoning is all about motor startup, not runtime. I've got a 2000W unit in my own wheeled setup and the reason I didn't go smaller is the fridge. A fridge might pull 150 watts running, but it wants three or four times that for a second when the compressor kicks in, and a 700 or 1000 watt inverter will sometimes trip on it and then you're standing there resetting the thing every twenty minutes at 2am during an outage. Same story with a furnace blower or a sump pump. So check the surge rating, not just the continuous number, when you're picking a size.

The catch with going big is the idle draw. My unit sips somethig like an amp or so at 24v just sitting on, wich over a whole day is real capacity gone for nothing. Mine has a power saving mode where it sleeps untill it senses a load, and that made the bigger unit practical. If the one you're eyeing doesn't have something like that, put a switch on the remote port and get in the habit of toggling it off between uses.

So I wouldn't buy 3000w, but I wouldn't box myself in at 1000 either. The middle of the range handles the annoying loads without the weight and standby drain of the monsters.

This is kind of where I'm at too, just starting my own box build. One thing I keep wondering about is heat. The big ones have little fans that kick on and they seem to run them a lot even with a light load. My box is closed up with the batteries in there too, so I'd worry the whole thing gets warm sitting in the sun. Does a smaller unit run cooler enough that it matters, or does everything get toasty inside a case like that either way?

The thing that settled it for me was the wiring, not the weight. I ran the numbers on putting a 3000w unit on 24v and at full load you're pulling around 125 amps continuous, which meant 2/0 cable and a 200 amp class T fuse to do it right. That stuff is heavy, stiff, and expensive, and suddenly your tidy rolling box has fat cables you can't coil up small. A 1500w unit gets by on 4 gauge and a 150 amp fuse and everything stays neat. Unless you've got a specific big load in mind, the copper cost alone will talk you down a size.

Back when I started messing with this stuff we were clipping cigarette lighter inverters onto a wet cell in the trunk, so anything with wheels and a panel on the lid feels like luxury to me. Here's how I handled your exact dilemma: I never put the big unit in the box. I keep a small 400w one permanently wired in the portable setup for camp stuff, and the big 3000w unit lives on a shelf at home with its own short cables. When the power's out at the house, the rolling box isn't going anywhere anyway, so I just carry the big unit over and hook it up there. Best of both without dragging 60 pounds of inverter around the campsite.

This is my first post here so forgive me if this is a dumb question, but why did you go 24v on a portable box? I built mine around a single 12v battery mostly because every little inverter and usb gadget I already own assumes 12v, and I figured that keeps replacements easy when something dies at a campsite. Is the series setup mainly about thinner cables or future headroom? Also curious how many watts that lid panel actually adds back on a good day, I keep eyeballing mine and wondering if it's even worth bolting on.