10M Rubber Soft Cable 18 AWG 0.75MM2 power wire 2/3 Cores Pins Copper – Appliance and Spares Company
AWG to MM2 – AtulHost
AWG conversion table
I bought a roll of 13-14 AWG wire (2.5mm2). According to this chart, I would be safe running a wire from my battery (which is next to my firewall), through the firewall,
Metric AWG to MM2 Conversion Chart – Mueller Group
AWG/SWG to mm/mm2, inch/inch2 & kcmil Calculator & Conversion