Latest update on my converter. Everything works noe. I changed the fuses on the - and radio. Thank you for your help. This group has saved me money!

Hello again, I installed the converter and how I have AC power, everything works normal. I have not installed my battery yet, I noticed that on the converter it has a red and white wire. The Red went to positive and the white went to neutral. The wires that attach to my batter are white and black. Is there a way that i can check to see which wire is the positive and which is negative? I don’t want to make a mistake and put them on the wrong terminal. Thanks