@marcusnilsson It depends on the used LED bar, at first if it use 12V, you have to count with 12V and not the voltage on the battery. 25A, 12V = 300 W is right, BUT have a look at the technical details of the lightbar you want to buy:
I bought a Hella 32“ Slim Lightbar, Voltage 10-30V, used A 8.9-12.5A, so W will be something around 120W.
The Lumen of the bar is important too, brands like Osram / Hella / etc. have at the same Lumen, the half or less consumption of cheap Asian parts.
At my Hella the a substitute cheap product have 368W…… Big difference. Hope that helps you…. And you can use every socket with 25A…