Very promising to use lithium to save weight and allow more draw down. I picked up a Renogy Firefly for testing an it has a 16amp hr lithium battery that put out very even voltage but at only 16 amp hrs, doesn't have the capacity of the Yeti 400. It ones have two 10 watt panels built in and inverter though.
Did some Yeti 400 testing on my 50 qt ARB and 18cf Dometic using the same watt meter Christophe used in his testing that I just read about.
Ran the ARB fridge inside with minimal opening for 28 hrs. Yeti showed voltage 11.72v, 248.3 watt hours, or a little over half capacity used. The display showed 40% so I plugged it back in. Max watts: 62.5, max amps 5.17.
Ran the Waeco/Dometic CF18 (which is surprisingly large with no 'crisper') for 42hrs, took 21.6 amp hrs, 263 watt hours with max draw of around 32 watts for the smaller compressor. I find myself using the small dometic more often as it is easy to transport and great for day trips to the trail or running errands when u want to hit grocery earlier in your run. Only downside I have found if there is no dedicated temperature control, just a knob which gives you an idea how old it will be. I have thermometers inside and now know that leaving the knob a bit shy of 1/2 way is about 35 deg F.
I am chaining one of my Yeti 400s with an Extreme 350 (with replaced battery) and seeing excellent run times for the ARB. I have a new dual zone fridge on the way and anxious to test it out and see how much juice it will take.
