The limit is 2000 watts. The Leaf needs at least 300 watts to sit around idle in park (with nothing else running). That puts the safe extraction value at around 1500 watts (to account for efficiency loses). I've had it extract that much power for literal days at a time, so there is nothing for anyone to be afraid of as long as proper precautions are put into place.
I agree that you would not just use battery clamps and run that much power for days, that's why I use a hard wired system and why I always make sure to mention that.
I've been doing this since 2015 with the Gen 1 Leaf and Gen 2 Leaf more recently, my math and electrical knowledge is solid.
Anyone who claims otherwise is more than free to look over my old post from the last decade where I document this and submit their own counter-evidence if they like.
The driver motor uses +500 watts of power when in creep mode from the traction battery, not the 12V system (when you let off the brake while in D or R and it moves slowly). When in park, it simply remains off. The +300 watts is just the water pumps, radiator fans, electronics, etc. It only gets that low though if you have absolutely nothing else turned on, like cabin fans, lights, seat heater, radio, etc.
you’re right about it getting hot only on the battery connection and not the wire itself. I re-did the connection using stronger torque on the battery screws and the inverter and they seem to be working a bit cooler now.
Get one rated for several times the rated current of tool. Motors tend to pull around 5-6x the continuous rated current on the rating label when starting. If your tool is rated for 5A and you get an inverter rated for 6A max., it is likely that the self-protection circuitry in the inverter will shut down it's output due to the starting peak current.
