How to test power output of an 8.5kW generator?

Question

I found a very cheap 8.5 kW AC generator which works on gasoline. Produces 220 V, 380 V and 12 V as output. Some people online say is fake and it can't have 8.5 kW, that it actually has 2 kW and the label is wrong. The seller assures me that he run a 7 kW industrial welder with it and works fine. The seller is also incentivized to lie or exaggerate.

I plan to go and test this generator myself. Trouble is, it's unwieldy to carry all this loads with me required for reaching a 8.5 kW consumption or close to that. I have a 2.3 kW motor, the motor is heavy, requires me to cut something like a tree trunk to know for sure, I have a big room heater rated for 2 kW but i only have 1. So basically i need to take my 3 angle grinders, my motor, my room heater, and maybe 2 other hair driers, move them 200 km away, then put them under load, just to test this :)) Sounds like a big complicated mess. And if I go there and ask the seller to bring all this devices to generate so much load, that's something he might not be supper happy about. I would like this to depend on me.

Is there a better way to add a lot of load?

What is that simple test one can do with ease and find out how good is a random generator?

Then I've been thinking about electrolysis. I can simply drill 2 plates of steel 20 cm by 20 cm, put them in a plastic water container, and let electrolysis draw power while the generator runs. Then using a multi-meter I can check the amperage. The voltage meter already exists on the generator.

Is this something which is likely to work? How big the electrolysis plates need to be for this to draw 8.5 kW of power? Is there some other easy way to do this?

Answer 1

Borrow some electric kettles from your friends, or buy a couple, they're not that expensive.

They're compact, and light when empty.

They have a very predictable current draw, not something that could be said for welders or angle grinders for instance. The power factor is unity, and there's no inrush current, so there will be no argument with the vendor that you're testing the generator under ideal loading conditions.

You need only three 3 kW kettles to get to up to 9 kW. See if you can get one or two lower power ones as well, so you can adjust your load finely to see what collapses the generator output.