The first cup of coffee - with onboard power!

For last Christmas (2014) my brother Winny gave me a nice present: a Waeco PerfectCoffee MC01 coffee maker, powered by just 12V. I had not yet dared to try it out, because of the anticipated power needed. The 12V version requires 170W (as of the manual; the website states actually 180W), which translates to 15A current. But now with the updated wiring which supports up to 30A I was finally in a position to give it a try.

So I filled in the coffee and the water and started the coffee maker. The voltage of the consumer circuit which had been at a healthy 12.9V dropped instantly to 10.8V. So I decided to start the car engine to give some power support with the alternator. Then the voltage went up to 12.0V in the consumer circuit. On the solar panel controller I could see that the battery voltage at that point actually was even much higher: at 13.2V because of the alternator, while the consumer circuit still was at 12V. The current draw of the coffee maker was then 13A.

This is because of the voltage regulator in the solar panel control which limits the voltage of the consumer circuits. Once I have my own control box ready, I will have some more clarity regarding the various voltages and the currents that flow in the electric system.

When I switched off the car engine to have the coffee maker powered only on by the battery, I did observe the battery voltage still showing a value of 11.7V, while the consumer circuit voltage was at 10.8V. The current draw then was 11A.

But in the meantime the coffee was brewing nicely.

And after about 12 minutes a cup of delicious coffee was ready. Excellent! Now I can be completely mobile and have a cup of coffee. Can surely be also made into a tea cooker. And all without the need for any gas bottle or gas cooker - GREAT!

The next test of a major appliance will be the batter-powered microwave oven - also a present from my technology-conscious brother Winny. For this one I want to have my junction box ready, so that I can see the power distribution of the required 30 or so Ampere...!

The fridge is broken!

For a while the refrigerator was standing in the rear of the vehicle, kept in place by bungee cords in order to avoid it falling over when driving. I had removed the compressor unit from the rear, which is one of the specific features of this Waeco CRP-40 refrigerator. It sat there stable, with the compressor / evaporator cage sitting next to it and attached to the vehicle wall so it would not move.

I already noticed that very little provision has been made by the manufacturers for a SAFE removal of that compressor. The compressor unit is mounted on a metal structure which is hinged into the back of the fridge and can be unmounted, so that this unit can be mounted up to 1.5 m away from the actual refrigerator box. This is very useful in situations where there is very little space, as in my micro camper, for example. That was the main reason for choosing this refrigerator.

But removing this unit was more difficult than I had thought. Some of the screws which needed to be unlocked were very difficult to access. And the main connecting pipe that connects the coolant to the fridge was dangling in the back without any stress relief support from the compressor. The pipe (aluminum) just was spirally wound up and could be bent so that the compressor unit could be mounted away form the fridge. But the full stress of any motion action was transferred to the copper part of the pipe directly at the compressor, and that pipe was already strangely bent, apparently during the manufacturing process.

So when I proceeded to put the compressor in its final place in the car and wanted to affix the refrigerator more permanently, I suddenly heard a hissing sound, and I saw that the copper pipe at the compressor had a hole in that section of pipe which was bent very strangely already from the very beginning. So here it was, a brand-new fridge, just 2 weeks old, and already broken now, not usable. I was quite pissed...

In the picture one can see the pent pipe. This was NOT my doing, the pipe had been squeezed and bent before I removed the compressor unit from the fridge. I should have taken pictures right when I installed the fridge to proof that and possible get a warranty repair. Apparently, the stress from moving that unit away from the fridge, with the tension and stress directly being transferred to the pipe, was too overwhelming for that weak spot.

I hereby need to warn all those who buy this refrigerator and are considering removing that compressor unit: take pictures before you do this, and document the state of the compressor pipes. Also, try to build some kind of mechanical stress relief, with some wood structural enforcement, to keep the pipe at this compressor cage in place and to make sure that it does not move in the vicinity of the compressor unit, when the whole unit is moved. I should have done that right away, but did not...

After the damage was done I continued to work on the mechanical structure for tightly putting refrigerator and compressor unit in place. I built a small shelf for the compressor, attached the flush mounting frame to the refrigerator, and built a structure with wooden beams to be fixed to the vehicle. First I thought of building a whole cabinet from bottom to top, hence I placed a vertical pillar in the rear. But then I decided that this would take away valuable space, as I thought of using the vertical space more for a bed that could sit on top of the whole fridge / electronics structure. So I cut that beam and added a more rigid horizontal structure. I was even able to use one of the panel mounting holes in the side of the vehicle where the original cover panel had been mounted. This allowed to rigidly attach one of the beams to the vehicle. In the pictures below one can see the little shelf for the compressor unit, which is attached to the panel covering the rear right seat belt, and which is also supported by a vertical beam. The compressor cage is held in place by those rigid slide-in mountings that were also in the back of the fridge. It stands on rubber feet on that shelf. I may bind it also down with some straps to ensure it does not move when I go over potholes and bumps in the road.

Refrigerator is installed!

On Wednesday the Waeco CRP-40 fridge arrived. Compressor, the smallest size model, with removable compressor which can be mounted up to 1.5 m away. I wired it up, and it is running fine, cooling down to 4 C. And with a small freezer compartment.

Somewhat no thrills, no light inside, no cover door for the freezer section. But very space efficient.

I also got a frame, which will make the fridge flush with the cabinet I am going to build around it. At the moment, it just stands in the rear of the vehicle, affixed with a few bunjee coords so that it does not turn over in tight fast curves.