1000W. I have a coil of cable at home that I bought for other wiring projects, along with a hydraulic lug crimper. I think the cable is 1/0 but I’ll have to check when I get home.You are correct, it's next to the breaker. What size inverter are you adding? The stock battery cables are only 6 AWG, I changed to 1/0 for my 2000W inverter.
I was debating about running it off the breaker but didn’t want to risk exceeding the rating.