gen 2 12 volt power inverter mods and connections main 12v buss

First success my inverter handles well at 300 watts and some spikes way way above could be way up there like 1000 + or higher for a split second or more. Been using for amplifier music playback for a few years. I finally decided to do some testing. All tests car on ready. Bosch battery new.... coffee maker draw 760 watts voltage dropped to 13.1 . Ground wire from battery to chassis got toasty after 2 min. test stopped.
Added 2 gauge ground strap from battery to chassis = 13.3 volts then dropped to 13.1 improvement on + feed temp also no ground point heat. Swapped in optima yellow for prius a bit better all around as far as voltage drop watts on coffee maker went up to 850 with optima doubling up my inverter cable size from a single 2 gauge + and neg to double same size. Decided to test the bosch hooked up to the inverter and the optima at same time to see what happens. No real difference seen in volts.
And now the limiting factor is the 12v wire size feed from the 12 v buss inside the cars inverter to battery and the grounds and of course how much the dc to dc converter can output.

Next experiment connect inverter directly to 12v jump point then find a good ground chassis run coffee maker test.

Now let me say inline fuse 60 amps from my inverter to the at the present time most conveniently accessible point of contact to intersect the 12v main buss out is jump terminal. So now fused access closer to main power source bypassing insufficient cable size voltage drop.....vs cars inverter cabling to its 12 volt battery 10 plus feet. And a larger wire closer with less voltage drop should be less stress on the dc to dc converter.

http://techno-fandom.org/~hobbit/cars/training/800/oak-i-bot.jpg

 

major improvement. + inverter cable got warm ran a single 2 gauge will upgrade that. Meter on inverter is not real accurate. When inverter fan turned on it dropped to 13.5 but that might not be accurate.