So let's change the question. Let's suppose I want to make up a boost converter from scratch. How do I know it's a 150W, 200W, 300W,... 1000W converter? I was wondering if it's the limit current capacity of the inductor. Also, the output voltage is limited by the capacitor voltage limit. So for the converter from Amazon, the maximum input voltage is 32V and the inductor current limit is 5A, this way the input power is 160W, due to some losses along the way I can get about 150W at the output, does that make sense?