ok I'm not expert on fridges but have messed around including building and installing the isotherm asu fridge in my last boat build. That was a utectic holding plate system and the electronic thermocouple failed after two years so we fitted a manual thermocouple to the existing unit.

Now the new fridge seems to have some fan system inside the fridge that blows cold air rather than makes a ice block With a utechtect plate.

so what I have noticed is that the compressor runs for half hour then shuts down but I can still here a fan running in the period the compressor is shut down hence I'm seeing my battery life last just a 24 hour period. I have 800 amp battery's
So it seems the fridge and freezer are not very energy efficent ......

can an someone shed some light on my refrigeration system?