Not exactly true - some (like the Suaoki) feature a regulated 12v power supply. I would modify your statement to say: "If you plan to run a fridge, make sure your battery pack has a regulated 12v power supply". Interestingly the low voltage can also be caused by voltage drop from a power lead that provides insufficient "ampacity" (too much resistance). I recently camped in a Sprinter 4x4 that had the factory (E28) aux battery option with 12v outlets in three areas of the interior. The one at the rear (where you'd most want to run a fridge) would not run my Dometic fridge and would exhibit the exact same symptoms you describe (begin a cycle, then immediately shut down). Once I moved the plug to the forward-most outlet (closest to the battery) it worked fine. Apparently Mercedes uses very small gauge wire to power the rear most socket, causing excessive voltage drop and thus triggering the "low voltage cutoff" of the fridge.Since all these goal zeros/jackerys/suaoki are basically the same 3s li-ion 10.8- 11.1 volt powerpacks, I decided to test the boost/buck converter on something similar. I used a very small mobius 3s powerpack, its only a 26ah battery at 10.8 volts. I connected to the fridge and ran it from 6 pm to 6 am, I unplug the fridge at 6 am the powerpack still had 30 percent left, so it could have ran it some more.