I wired mine though the big rubber grommet and also connected a remote power meter where the inverter wire connected to the battery so I can monitor the battery voltage as well as the amount of power being pulled by the inverter. In addition, the inverter I use includes an app for monitoring usage and voltage duplicating and eliminating the need for the power meter. In addition, I can turn the inverter on and off remotely through the app. Amazon.com: kinverch 2000W Continuous/ 4000W Peak Power Inverter 3 AC Outlets 12V to 110V Car Converter with USB Port : Clothing, Shoes & Jewelry
I hope this helps you.
I hope this helps you.