Car Fridges

Nobby, first of all you have to compare apples with apples, not apples to melons.
Your figures on the Trailblaza are most definitely incorrect. 42 amps is the mark for that fridge.
In the rest of the figures you are quoting, you are not quoting the size of the fridges that go with those figures.
The Engel was only 40 litres
The evaKool was 50 litres
The Weaco was 40 litres
The Trailblaza was 40 litres
Now if you work those figures back to litres for power consumed the evaKool works out the best.
No reason at all you should not go for the cheaper fridge, as all the Danfoss powered fridges are good. If you are going on bad roads constantly, the evaKool is the only fridge on the market that uses the IndelB suspesion system, which Danfoss have on their website as being the best suspension system available for their compressors. That is the system used on all the NATO fridges with Danfoss compressors.
At least with a Danfoss powered fridge you can get it repaired anywhere if necessary and is unusual to need repairs, and they are easily and cost effectively repaired unlike Engel.

Charging deep cycle batteries with an alternator of that capacity will ensure the batteries are not going to have a very long life. You would be far better off buying the small Honda GX100 motor for $460 and getting a Lucas generator and three barrel regulator fully rebuilt from your local auto electrician for about $160 and hooking it up to the motor. You can also put a small relay on the system to automatically cut the motor off as soon as the batteries were fully charged. Noise with a C20 generator is not going to be much of an issue as you would only need to run the Honda motor at around 1/3 throttle. Charging batteries is far superior to charging with an alternator, and ensures the batteries get fully charged. Those Christie built generating sets are good for people with heaps of money that can afford to regularly replace their batteries, or just use them once or twice to start earthmoving gear in the field. They are most definitely not good for charging deep cycle batteries on an ongoing basis, and are unlikely to charge the batteries to full capacity. A generator for example will charge at 20 amps continuously till the battery is *fully* and properly charged. An alternator will start at say 50 amps, as it is totally voltage dependent on what amperage it will charge at, and quickly reduce down to say 10 to 15 amps while the motor is still screaming its head off, and as the battery gets up, it drops down to say 5 amps and the battery is still not fully charged. Where as a generator stays at the 20 amps all the time it is charging the battery and only drops down once the battery is charged. If you take a 55 amp alternator and a 20 amp generator, there will be virtually no difference in the amount of time taken to charge the battery. But of course the generator will have charged the battery 100% where as the alternator at best will have charged it 90%. Now 10% may not sound like much difference, but in practices that is probably 25%+ of the battery capacity. Unfortunatly everything in the auto electrical field is not black and white, you need to know how these devices work and function.

Do you really need two batteries. One battery should be more than sufficient for 2 days running including lights. More batteries always equal more problems.

Have you considered solar panels instead of a gen set. You can do solar panels for the same price as a Christie gen set and never have to bother with fuel, servicing or replacment cost as solar panels have 25 year warranty.

Ozi.. Thanks for the reply. My Trailblaza figures are taken from their spec. sheet on a 60 litre model. They claim the following:
22 amp/24hrs @ 25deg
32 amp/24hrs @ 35deg
46 amp/24hrs @ 45deg.
They might have a slippery grip on the truth!!!. Anyhow it looks like the Evakool will get the dollars. The reason for the twin batteries is that they are already on the CampOmatic that I have just purchased. I will check your theory ( and I'm sure it is right after reading your answers in the past) with my Auto Elect. and will probably end up buying a Honda EU10i, certainly not because I'm flush with $, but because I don't want any hassels when travelling, and Honda put out a good and reliable product.

Nobby, I have an old Overlander magazine with a fridge comparison in it. One of the fridges is the 60L Trailblaza. The test results were;

23 amps @ 24 deg C - 4.5deg C inside
30 amps @ 35deg C - 4.3 deg C inside

Bear in mind that while the tests were carried out over 24 hours, this did not include any openeing or closing of the fridge, for which which draw many more amps. The comparison included fridges of many different sizes, but was very interesting.

For interests sake (figures for 12 hours at 35 deg C, 12 hours @ 24 degC)

Explorer 56L: 37.09 Amps/day Engel 29 L: 20.81 amps/day
Indel B 52L: 27.59
Swagman 60L: 40.25
Kidmans 45L: 26.5 (fridge is based on Evacool box NLA??)
Trailblaza 60L: 26.33
Autofridge 39L : 14.81

Please note also that all fridges were set at around 4 degC and were cooled to this temperature when the stop clock was started.

Cheers.