Look, it is easy, dont trust the model labels, I have seen them say Super 450, buts its 250w, "Super 450" is a model number not a descriptive of the product.
But people are lazy at reading the fine lines and the manufacturers knows this..
But you have a label with the 12v and related amperage to it, and if you apply the laws of Ohms (Voltages*Amperage = Watts) you get 12v * 18A = 216 Watts. + another 12v * 1A=12 Watts grand total of 228Watts in reality... so yeah not what you expected.
but now you know