No doubt the compressor start power requirement is causing your problem. I installed a dedicated inverter for my Kitchen Aid residential refer in the Bus, and also use it to power a 17 cu ft chest freezer and a 1.5 cu ft basement freezer when we bring fish down from Alaska. Since it's the start current that causes the problem we chose a Tripp Lite PV1250FC modified sine wave inverter because of it's HUGE ability to deal with input surges. It's not just the input surge, but how long the inverter can maintain the surge input. This inverter will handle it all. We used a similar one in our 2008 Bus and now our 2013, and have never had a problem with it with over 7 years of use.
