I used to run my 450 watt inverter from the 12 volt plug by the antenna hookup in the cabinet above the front seats. It ran my tv, dish box & dvr. But it would only run it for a few hours and then the inverter would start beeping indicating low power & the tv would shut down. I would run the engine to recharge the battery to get by for longer.
After reading Handy Bob's blog in which he described my exact problem and the solution, to run a shorter dedicated heavier gauge wire from the battery to the inverter, I did just that. I discovered the wiring from the battery to the 12 volt outlet ran over 20'. So now it's 6', 10 gauge, and went from beeping at 90% soc to now working below 70% soc.
https://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/
