I am currently looking at a 32 inch 310 watt LED light bar for my 2010 Honda CRV. The light bar I am looking at is https://www.amazon.com/dp/B07MCNYXFT/ref=cm_sw_r_cp_apa_i_JpKPDbTR3J8R4.
The wiring harness I am looking at is https://www.amazon.com/dp/B074GYNJ85/ref=cm_sw_r_cp_apa_i_mqKPDb9945BNQ.
On Amazon it says that the wiring harness could handle up to 400 watts. However when I look at a calculator for wiring harnesses by gauge size, I get confused and it looks like it can't handle the load from the light bar.
The light bar will be connected to a 12 volt battery and since it is 310 watts I'm assuming that it would take 25.83 amps and from what I found 12 awg wire can only handle 20 amps.
I was looking to see how would I be able to know for certain that a certain gauge wire could handle a certain appliance. Thank you.