I have a Vitrifrigo c51is.
I added more insulation to the box, and insulated the cabinet in which it resides.
This extra insulation allowed me to move the 120MM fan to the other side of the condenser so that it pushes air across the condenser, then compressor and compressor controller. I made a cover over the cooling
unit portion so that cool filtered air is sucked from below the fridge, through the condenser and out the cooling
unit tunnel and this heated air has no chance of being recycled. It is pushed out of the cabinet after one pass by the same fan.
I also used a new Quiet Noctua Nf-f12 fan which is ~53 CFM and 0.05 amps to replace the Vitrifrigo provided Noisy ~72 cfm fan that drew 0.13amps.
I do have another 0.05a 80MM fan in the adjacent cabinet running 24/7 that causes a steady slight flow of air through fridge airpath.
I also added a 0.03a 40MM ~6 cfm fan to the interior
, taking power from the light. it too runs 24/7 and blows into the freezer compartment. With the fan a setting of 2.2 of 7 keeps the entire interior
under 34F. Without the fan I need a setting of 4 of 7 to get all locations under 36.5 F, and some of them will be 27F.
I Own a GTpower inline watt meter, very similar to the 'watts up' meter. I replaced the aluminum
12awg wire with tinned 8 awg right to the circuit board and use 45 amp anderson powerpoles.
When I hook this inline on my fridge, It took over 5 days before It measured 60 amp hours in an average ambient temp of 70F, and normal use, opening multiple times daily and adding foodstuffs, and beer
. The GTpower meter cannot read loads under 0.05a, so I add 1AH consumption to the reading for every 24 hours to account for the other fans I run for the fridge.
Best way to increase efficiency of these fridges is to make sure the compressor and condenser are not bathed in hot air that they themselves have heated.
The Danfoss BD35f can power upto 0.5a of 12v fans. One can add another fan to exhaust
the cabinet where the cooling unit resides. it will only run when the compressor fires up.
It could power 10 Noctua NF-f12 fans if it had to. Don't just use any computer fan, they vary greatly in air moved for current
consumed and Noise
made. They all do better when pushing air through a condenser, rather than pulling it through, and are quieter doing so.
Let that cooling unit breathe and your batteries will thank you.
Also you state that you have a 60 amp charger which 'tops off the batteries quickly' If these are Lead acid batteries, you are not getting from 80% to 100% State of charge in under 2 hours no matter how much confidence you have in your charger or its marketing
. 4 hours is more reasonable to reach a true 100% charge from 80% and that is with a higher absorption voltage than most chargers do.
So it is likely your batteries are now capacity compromised from chronic undercharging due to the misbelief that lead acid batteries can be quickly returned to full charge.
Here is my cooling unit tunnel:
The tunnel also serves to protect the cooling unit on insertion and removal
as it is a super tight fit in my cabinet:
This fans location makes it much easier to clean the fan blades and condenser fins too as dust build up is an issue:
I added an air filter to the intake to keep the dust build up to a minimum. The filter turns black all too quickly.
There is certainly good airflow when the compressor kicks on: